Executive summary

In the Driver's Seat II: Beyond the Early Driving Years is the second report from the collaborative partnership between the Australian Institute of Family Studies, the Transport Accident Commission of Victoria and the Royal Automobile Club of Victoria. It further explores the driving experiences and practices of young Victorian drivers, drawing upon data collected as part of a unique Australian study - the Australian Temperament Project (ATP). The ATP is a longitudinal community study that has followed the development and wellbeing of a large group of Victorian children over the first 24 years of life. Starting in 1983, fourteen waves of information have been collected from parents, teachers and young people via mail surveys. Information on young people's driving histories and practices has been collected at 19-20 and 23-24 years of age. The first report, In the Driver's Seat: Understanding Young Adults' Driving Behaviour (Smart & Vassallo, 2005), focused on young people's experiences while learning to drive and their driving practices during their first years of licensure, as well as identifying child and adolescent antecedents of differing problematic driving behaviours, reported at age 19-20.

This second report focuses on young people's driving behaviours at 23-24 years, as reported by 1,000 study members, with six main issues addressed:

• young people's driving behaviours, with comparisons of males and females, and of young people in differing occupations, with differing levels of educational attainment and from urban or rural areas;
• the consistency of driving behaviours from 19-20 to 23-24 years;
• links between drink-driving and other types of risky driving, and between risky driving and substance use;
• overlaps between crash involvement, high-level speeding and fatigued driving;
• the influence of parents on young people's car purchases; and
• links between young people's personal characteristics and their driving behaviours.

Driving behaviours of young people in their mid-20s

Overall trends

Almost all young people (97%) had obtained a driver's licence by 23-24 years of age, with the average length of licensure being almost 6 years. About 7% had experienced a licence cancellation or suspension since first gaining their licence. Approximately half had been detected speeding during their driving careers, and 60% had been involved in a crash while driving since gaining their licence. Crashes resulting in property damage were the most common, while crashes resulting in injury or death were very rare. Most driving took place during the daytime on weekdays, with the average time spent driving at these times being five hours per week. Young people spent less time driving at night or at weekends. Risky driving was relatively common. For example, on one or more of their ten most recent driving trips, close to half had exceeded the speed limit by 11-25 km/h, about two-thirds had driven when very tired, two-thirds had used a mobile phone function (such as receiving or sending an SMS), and around half had talked on a mobile phone. One in five 23-24 year-olds had driven when near or over the legal alcohol limit during the previous month. Over 40% had friends who engaged in drink-driving, and about one in eight had a partner who had driven when over the legal limit. Two-thirds of young people “always” made plans to avoid drink-driving, and about three-quarters of those who made plans did not subsequently engage in drink-driving. The most common strategies used to avoid drink-driving were to plan ahead and arrange alternate transport to their destination (e.g., have someone else drive, take a taxi or ride on public transport), or to alter their drinking habits (e.g., not drink at all, or reduce the amount of alcohol consumed).

Gender differences

Young men and women significantly differed on many aspects of driving. Young men had more often had their licence cancelled or suspended, and while there were no differences in the occurrence of crashes, young men had more often been apprehended for a driving-related offence. Additionally, they tended to engage more frequently in a range of unsafe driving practices (e.g., high-level speeding, driving when affected by alcohol). On the other hand, young women had more often driven when fatigued. Young men were also more likely to be among the small group who rarely made plans to avoid drink-driving, and to more often end up drink-driving if they had made such plans. There were also gender differences in the strategies used to avoid drink-driving, with young men being more likely to alter their drinking habits (drinking less, counting or spacing their drinks, or drinking low-alcohol beer), and young women more often abstaining from drinking altogether.

Occupational status

Young people were divided into groups according to their occupational status as classified on the ANU-4 Occupation Status scale (Jones & McMillan, 2001). Low, average and high status groups were formed (25%, 51% and 24% of the sample respectively). Very few differences were found in the three groups' driving histories and behaviours, for example in their licensing history, driving patterns, crash involvement or rate of apprehension for driving-related offences.

Educational attainment

Three groups were formed on the basis of the highest level of education that young people had completed: Year 12 or less (30%), post-secondary education but not university (26%), and university (44%). Most differences centred on the university-educated group. These young people had less often been detected speeding, were less likely to have had their licence cancelled or suspended, were less likely to have friends who were drink-drivers, more often used forward planning when making plans to avoid drink-driving, and were less likely to drink-drive after making these plans.

Residence locality

Young people living in metropolitan (68%) and non-metropolitan (31%) areas were compared using the Australian Bureau of Statistics “met” and “ex-met” categories (capital city statistical division vs the rest of the state). As a group, those from metropolitan areas had more often been involved in a crash, and had been involved in a higher number of crashes. Additionally, rates of hands-free mobile use when driving were higher among young people from metropolitan areas, whereas non-metropolitan drivers were more likely to have not worn a seatbelt when driving. While there were no significant differences in the occurrence of drink-driving, differences were found in the strategies used to avoid it. Whereas non-metropolitan drivers were more likely to leave their car behind and find an alternate way home (e.g., be driven home, take a taxi or public transport, find another way home), metropolitan drivers were more likely to alter their drinking habits (e.g., drink less, count or space drinks, or drink more water or soft drinks).

Consistency of driving behaviours from 19-20 to 23-24 years

Driving trends across the whole sample were examined to determine whether young people's driving tendencies remained similar or had changed as they gained more experience on the road. There was a slight decrease in high-level speeding and driving without a seatbelt from 19-20 to 23-24 years among the ATP sample; however, rates of other types of risky driving tended to increase or remain stable. Driving when fatigued remained very prevalent, and driving when affected by alcohol increased substantially. Thus, when 23-24 year olds did engage in risky driving, they did so almost as frequently as did 19-20 year olds. This suggests that (when present) risky driving is as serious an issue in the mid-20s as in the late teens, and points to the importance of sustaining road safety efforts into the twenties. Young people identified as showing high, moderate and low levels of risky driving at 19-20 years were followed forward to determine whether they would continue to show similar driving patterns at 23-24 years. High stability was found among those with low levels of risky driving, but less stability was found among those showing moderate and high levels, the majority of whom were less problematic at 23-24 years. The benefits of young people not engaging in risky driving in the early years of their driving careers were highlighted, since very few subsequently became high-level risky drivers. Encouragingly, the findings demonstrated that young problem drivers were not destined to continue posing a road safety risk as they grew older, with improvement found to be common.

Risky driving and substance use

Early adulthood can be a period of considerable risk-taking: the prevalence of substance use reaches a life-time high (Spooner, Hall, & Lynskey, 2001), while other forms of risk-taking common at this age include antisocial behaviour, gambling and risky driving. Little is known about the degree to which risk-taking co-occurs among young people in their mid-20s. Accordingly, the co-occurrence of risky driving and substance use was investigated. Two main questions were explored. First, we investigated whether young people who engaged in drink-driving were more likely to engage in other types of risky driving. This was found to be the case, with speeding, and driving without a seatbelt, when fatigued, under the influence of an illegal drug or when using a mobile phone, all being considerably more common among young drink-drivers than among other young drivers. Second, young people who showed high, moderate and low levels of risky driving were compared on their engagement in substance use. Binge drinking, and marijuana, ecstasy and amphetamine use were all significantly higher among high- and moderate-level risky drivers, with the strongest differences being found on binge drinking and marijuana use. Further, high- and moderate-level risky drivers were more likely to engage in multi-substance use, and did so more frequently than low-level risky drivers. Risky driving appeared to be one element of a risk-taking lifestyle for a number of young people. Thus, young risky drivers would likely benefit from interventions that not only target their behaviour on the road, but also other aspects of their lives, suggesting a role for more broad-based “common solutions” approaches in addition to targeted approaches to road safety.

Crash involvement, speeding, fatigue and other aspects of road safety

As well as looking at whether risky driving co-occurred with substance use, the overlap of differing types of road safety behaviours themselves was explored. Inter-connections between three problematic driving outcomes - crash involvement, high-level speeding and fatigued driving - were investigated. Considerable similarity was found in the driver histories and behaviours of young people who had been involved in multiple crashes as drivers, had recently engaged in high-level speeding (more than 25 km/h over the limit), or had recently driven when very tired. Thus, higher rates of apprehension for driving-related offences and engagement in a wide range of other risky driving practices were evident. Further, 57% of those who had experienced multiple crashes since starting to drive, 72% of high-level speeders, and 45% of fatigued young drivers had engaged in another of these three problematic driving outcomes. These findings suggest that problematic driving does not occur in isolation, and may reflect a risk-taking approach to driving among some young drivers.

Parents' influence on young people's car purchase

Parents can play an important role in the driving behaviour and attitudes of young people. One way in which this may occur is through the advice and support they provide when young people are purchasing a car. Approximately 80% of 23-24 year olds had purchased a car since gaining their licence, and close to two-thirds of their parents had helped with the choice of a vehicle. Of these parents, almost 90% thought they had influenced their son's/daughter's choice to some degree, with about 30% feeling they had had a large influence. Parents were more likely to have had an influence if the relationships between the young people and their parents were close. Parents are not often considered in road safety efforts targeted at young drivers. However, there may be scope to make greater use of their influence, most obviously in relation to young people's purchase of a vehicle, but also more generally in relation to young people's driving behaviour and attitudes.

Personal characteristics

Links were explored between young people's propensity for risky driving and their personal strengths (social skills, temperament style) and lifestyle factors (employment, relationships, “settling down”). Individuals who drove in a law-abiding manner tended to show greater empathy, responsibility and perspective-taking than other drivers, as well as closer connections to parents and more tolerant attitudes. These findings are a reminder that what an individual is like as a person impacts on his/her behaviour behind the wheel. They point to the value of helping young people gain an understanding of their personal style and how this might affect their approach to driving.

Conclusions

The findings of this second report build upon those from the first report to increase our understanding of the road safety behaviours of young Victorians at an age that has often been overlooked - the mid-20s. The report provides an examination of the degree to which young people engage in risky driving practices once they have become experienced drivers, as well as the continuity of risky driving beyond the novice driving years. The findings provide significant Victorian evidence that can inform intervention and prevention efforts aimed at reducing risky driving among young people.

1. Introduction

This is the second report from the collaborative partnership between the Australian Institute of Family Studies, the Transport Accident Commission of Victoria and the Royal Automobile Club of Victoria. The collaboration began in 2002 when the Institute was commissioned to collect and analyse data on the driving experiences and practices of young Victorians, using data from the Australian Temperament Project (ATP) research study. The first report, In the Driver's Seat: Understanding Young Adults' Driving Behaviour, was prepared by Smart and Vassallo in 2005.

The Australian Temperament Project is a longitudinal study which has followed the development of a cohort of Victorian children from infancy to young adulthood, with the aim of tracing pathways to psychosocial adjustment and maladjustment across the lifespan (Prior, Sanson, Smart, & Oberklaid, 2000). The initial sample comprised 2,443, 4-8 month old infants and their parents, who were representative of the Victorian population when recruited in 1983. Fourteen waves of data have been collected thus far, using mail surveys, with the young people aged 23-24 years at the last collection in 2006. Parents, teachers and the young people themselves have responded to the study at various stages of the young people's development.

1.1 Major findings from the first report

The first report from the collaborative partnership (Smart & Vassallo, 2005) examined three broad issues:

• the learner driver experiences and driving behaviours of 19-20 year olds:
• precursors and correlates of three problematic driving outcomes (risky driving, crash involvement and speeding offences): and
• connections between risky driving at 19-20 years and other problem behaviours (substance use and antisocial behaviour).

Learner driver experiences and driving behaviours

Eighty-six per cent of the young people had obtained a probationary car driver's licence by 19-20 years of age. While there was considerable diversity in the number of professional driving lessons young people had undertaken, most commonly this was between one and five and seldom more than ten. About 80% had practised driving on at least a weekly basis when learning to drive; typically with their parents. While some stress or conflict was common during practice sessions with parents, this was generally minor.

In terms of young people's more recent driving patterns, there was considerable variability in the number of hours that young people spent driving at different times of the day and week. However, on average, young people spent a total of 5 hours on weekdays and 3 hours on weekends driving during daylight hours. Night-time driving was less frequent, occurring, on average, for 2½ hours during the week, and 2 hours on weekends.

Forty-three per cent of young drivers had been involved in a crash since gaining their licence, while approximately 30% had been detected speeding by police at least once.

Speeding was the most common unsafe driving behaviour reported by this 19-20 year old cohort. Driving when fatigued was also relatively common. Other unsafe driving behaviours, such as failing to wear a seatbelt and driving when affected by alcohol or illegal drugs were less prevalent. Young men engaged in unsafe driving behaviours more often than young women (particularly speeding, driving when affected by alcohol, and non-seatbelt use), and were also more likely to have been detected speeding by police.

Precursors and correlates of risky driving, crash involvement and speeding

The precursors and correlates of three problematic driving outcomes - risky driving, crash involvement and speeding - were investigated. Groups exhibiting low, moderate and high levels of each outcome were identified. The precursors and correlates of each outcome type were then investigated by comparing the resultant groups on a wide range of characteristics assessed at 19-20 years or earlier in life.

Young adults in the groups exhibiting high-level risky driving, multiple crashes and/or multiple speeding violations differed from other drivers on a wide range of domains. They tended to be more aggressive; engage more frequently in antisocial acts (for example, property offences or violence); have a less persistent temperament style (have difficulty in seeing tasks through to completion); use more legal and illegal substances; and have friendships with peers who tended to be involved in antisocial activities. In addition, young people in the high-level risky driving and/or multiple speeding violations groups tended to be more hyperactive, less cooperative, and had experienced more school adjustment difficulties than other drivers.

Common precursors shared by the high-level risky driving and multiple crashes groups were a more difficult parent-child relationship and a tendency to use less adaptive coping strategies. There were also some personal attributes and environmental characteristics that were uniquely associated with each driving outcome.

Group differences tended to be more powerful, more consistent and emerge earlier (in mid- to late childhood) among the risky driving and speeding violation groups than among the crash involvement groups (which emerged in mid- to late adolescence).

Relationship between risky driving and other problem behaviours

The degree of overlap of different types of problem behaviours was explored in two ways. Firstly, in order to identify common and unique risk factors, the longitudinal precursors of risky driving in early adulthood, adolescent antisocial behaviour, and adolescent multi-substance use were compared. Some overlap was evident, with aspects of temperament style, behaviour problems, school adjustment and interpersonal relationships predicting all three types of problem behaviour. Secondly, levels of antisocial behaviour and substance use among 19-20 year old low-, moderate- and high-level risky drivers were examined. High-level risky drivers engaged more often in antisocial behaviour and used alcohol, marijuana or both substances more frequently than less risky drivers. Furthermore, looking back in time, high-level risky drivers had displayed higher levels of antisocial behaviour and substance use during adolescence.

1.2 The second report

Considerable attention has been devoted to understanding the driving behaviours and characteristics of young, novice drivers. This focus is understandable, given the evidence that novice drivers are approximately three to four times at greater risk of being involved in a crash resulting in injury or death than older drivers (Cavallo & Triggs, 1996; Clarke, Ward, & Truman, 2002)

However, much less attention has been given to the on-the-road behaviours of young drivers past the early years of their driving careers to see how their driving patterns and behaviours change as they mature and gain driving experience.

The collection of a second wave of road safety data among the ATP cohort at 23-24 years, provided a valuable opportunity to examine the driving practices and experiences of this cohort of young Victorians at a later stage of their driving careers. Thus, the collaborative partnership between the Australian Institute of Family Studies, the Royal Automobile Club of Victoria and the Transport Accident Commission of Victoria was extended, enabling an exploration of issues such as the stability or change in young people's approach to driving from the pre- to mid-20s, as well as a more detailed focus on specific road safety issues that are of particular concern at this life stage (such as drink-driving).

This second report focuses on six broad issues that can further increase understanding of the driving behaviour of young Victorians. These are:

• the driving behaviours and experiences of young people in their mid-20s;
• the consistency of driving behaviour over time (between the ages of 19-20 to 23-24 years);
• links between drink-driving and other forms of risky driving, and between risky driving and alcohol or other substance use;
• connections between crash involvement, high-level speeding, fatigued driving and other aspects of road safety;
• the influence of families on young people's car purchases; and
• links between 23-24 year olds' personal characteristics and their driving behaviours.

2. Australian Temperament Project

The Australian Temperament Project is an ongoing longitudinal study that has followed the development of a large group of young people born in the state of Victoria, Australia, from infancy onwards (for a fuller account see Prior et al., 2000, or visit the ATP website <www.aifs.gov.au/atp>). The project is a collaboration between researchers from the Australian Institute of Family Studies, the Royal Children's Hospital, the University of Melbourne and Deakin University. It is led and managed by the Australian Institute of Family Studies and is supported by a grant from the Australian Research Council. The research presented in this report was supported by the Transport Accident Commission of Victoria and the Royal Automobile Club of Victoria.

2.1 Survey methodology

The ATP commenced in 1983 with a representative sample of 2,443 infants and families from rural and urban areas of Victoria. Participants were recruited from a subset of Victorian local government areas selected by the Australian Bureau of Statistics to provide a representative sample of the state's population in terms of parental education level, occupational status and ethnic background. All parents with an infant aged between 4 and 8 months who visited their local Infant Welfare Centre¹ in the chosen local government areas during the first two weeks of May 1983 were invited to participate in the project. At that time, Infant Welfare Centres were very widely used, making contact with roughly 94% of all live births. As a final step in the recruitment process, comparison of the recruited sample to Census data confirmed that the sample was representative of the state's population (Sanson, Prior, & Oberklaid, 1985).

Fourteen waves of data have been collected via mail questionnaires to date. The first four waves of data were collected at annual intervals from infancy to 3-4 years of age. From the commencement of primary school up to 19-20 years, the data collections were conducted at two-yearly intervals, with an additional assessment completed during the first year of secondary school in order to track children's adjustment and wellbeing over this important developmental transition. More recently, there was a four-year gap between the survey waves at 19-20 years and 23-24 years.

The questionnaires have assessed many aspects of the young peoples' lives, including their temperament, health, social skills, behavioural and emotional problems, risk-taking behaviours, educational and occupational progress, and peer and family relationships, as well as family functioning, parenting practices and socio-demographic background.

At every survey wave, parents have completed questionnaires about aspects of family life and their child's functioning. School teachers also reported on the child's school and social progress, personal adjustment, and temperament style at the preparatory grade, Grade 2 and Grade 6 survey waves. From the age of 11 onwards, the young people themselves have completed questionnaires regarding a range of topics, including relationships with others, attitudes and beliefs, and personal adjustment. The availability of data from multiple informants for most domains and at most survey waves has provided researchers with a rich and reliable account of this cohort as they have progressed from infancy to early adulthood.

Approximately two-thirds of the original cohort is still participating in the study after 24 years. A higher proportion of the families no longer participating are from lower socio-demographic backgrounds or include parents born outside Australia. Nevertheless, there are no significant differences between the retained and no-longer-participating subsamples on any infancy characteristics.

The findings presented in this report are based on a sample of 1,000 young adults (61% female), who participated in the most recent survey at 23-24 years. This represents a response rate of 67% of those who were still involved in the study at this stage.

Driver behaviour measures

At the 2006 data collection wave, at 23-24 years of age, study members completed a series of questions about their driving experiences and behaviours. Parents provided parallel information on these topics. The measures used to assess these issues are summarised in Tables 1 and 2.

Statistical analysis strategy

Throughout this report, a number of statistical tests are reported in relation to each topic under investigation. When multiple statistical tests are undertaken, the likelihood of Type 1 error (a finding of significant differences when there is no such difference) is increased. To reduce this risk, an adjusted significance level of p < .01 is used. For reader interest, results that are significant at the conventional p < .05 level are reported as trends, but are not interpreted.

For categorical data, Pearson chi-square and logistic regression analyses were undertaken, with inspection of standardised residuals used to identify cells in which there was a significant departure from chance. For continuous data, t tests and analyses of variance were undertaken, with post-hoc tests used to investigate specific group differences.

3. Driving behaviour trends at 23-24 years of age

This chapter provides a description of the driving behaviour of the 23-24 year-olds participating in the ATP study, with a particular focus on their typical driving behaviours, their history of crash involvement and driving-related offences, and their engagement in a range of risky driving behaviours, including drink-driving. This is followed by an examination of trends for:

• young men and women:
• young people living in metropolitan and non-metropolitan localities;
• young people employed in low-, average- and high-status occupations; and
• young people with differing levels of education.

3.1 Total sample trends

Licensing

Young people were asked whether they had ever held a car or motorbike licence. As shown in Table 3, almost all 23-24 year olds (97%) had held a car licence, but only 6% had ever held a motorbike licence. Very few were learner drivers or had never held a licence or permit to drive a car or motorbike.

Note: Percentages do not add to 100% as some individuals fit more than one category (e.g., has held both a motorbike and car licence).

The following discussion focuses on all study members except those who had never held a licence or permit (n = 974, 97%).²

Of those who had ever held a car or motorbike licence or permit, the vast majority reported holding a full licence (Table 4). Less than 1% were currently without a licence, and very few currently held a probationary licence or a learner's permit (about 3% in each category).

Note: Percentages add to slightly more than 100% as respondents could select more than one response (e.g., holds both a full car licence and a probationary motorbike licence).

There was considerable diversity in the length of time licences had been held, with the average being 71.2 months (SD = 15.5), which equates to almost 6 years. Seven per cent (n = 67) had experienced the cancellation or suspension of their licence at some time.

Time spent driving

Weekday driving during daylight hours was the most common form of driving reported by young people, with the average length of time spent driving at these times being approximately 5 hours per week. Considerably less driving was undertaken at other times, with night-time driving at weekends being the least common type of driving (Table 5).

Nevertheless, there was considerable variability in the number of hours young people spent behind the wheel at different times of the day (daylight vs night-time hours) and week (weekdays vs weekends), as displayed in Figure 1. For instance, while half the sample spent three hours or less in weekday daytime driving, about 16% said that they usually drove for ten or more hours at these times. Similarly, while the majority drove for one hour or less at night on weekends (about 60%), a very small number (2%) spent six or more hours driving at this time. The range of driving hours was quite broad, ranging from 0 to 20 hours for night-time weekend driving, and from 0 to 60 hours at all other times.

Figure 1. Number of hours typically spent driving per week, at weekdays and weekends and during daylight and night-time hours, at 23-24 years

Crash involvement

Sixty per cent of young people (n = 576) had been involved in a crash when driving since gaining their licence. Table 6 shows the percentage of respondents who had been involved in differing numbers of crashes during their driving careers.

Note: Percentages do not add to 100% as some individuals who indicated that they had been involved in a crash did not provide information on the number of crashes in which they had been involved.

Close to a third of all drivers had been involved in only one crash, while one in five had been involved in two. Relatively few young drivers (less than 8%) had been involved in more than two crashes over the course of their driving careers, with the highest number reported being six crashes. The average number of crashes reported was 1.0 (SD = 1.1).

Young people were also asked about the circumstances in which the crash(es) had occurred, (e.g., whether or not passengers were present) and about crash outcomes (e.g., whether the crash had resulted in property damage only, or someone being injured or killed).³ About half (48%) of all drivers had been involved in a crash resulting in property damage when driving alone. Property damage crashes when young people were carrying passengers were also quite common, with more than one in five (22%) having been involved in a crash of this type. Very few had been involved in a crash in which someone had been injured or killed, irrespective of whether they had been driving alone (3%) or when passengers were present (less than 1%).

Few 23-24 year olds (n = 26, 3% of all drivers) had been fined or charged as a result of a crash. Most of these drivers (n = 24, 92%) had been fined or charged once. The remaining 8% (n = 2) had been fined or charged twice.

Detection for speeding and police contact for driving-related offences

Table 7 shows the number of times 23-24 year old study members had been detected speeding over their driving careers, according to self-reports.

While 42% had never been detected speeding, about one in five had been detected once, and over a third had been detected multiple times, with the highest number being 15. The average number of times of being detected speeding among all drivers was 1.5 (SD = 2.3).

Young drivers were also asked how often in the past 12 months they had been in contact with police for a driving-related offence. While the great majority (n = 862, 86%) reported no contact, 12% (n = 122) had been in contact with police for a driving offence on one or two occasions in the past year. Only 1% (n = 13) reported this type of police contact on more than 2 occasions.

Risky driving

The percentage of 23-24 year olds who had engaged in differing unsafe driving practices during their last ten trips is shown in Table 8. Risky driving behaviours include speeding, driving without a seatbelt (or helmet if on a motorbike), driving when very tired, driving while under the influence of alcohol or illegal drugs, and using a mobile phone while driving. The average number of trips in which this sample of young people had engaged in each type of risky driving is also is shown.

The most common type of risky driving was speeding by up to 10 km/h over the speed limit, with more than four out of five young people having done so at least once during their last ten trips. This behaviour had occurred on about a third of the past ten trips. Driving between 11 and 25 km/h over the limit was also quite common, with about 45% exceeding the speed limit by this margin at least once during their past ten trips. Across the sample, the average number of recent trips during which young people had exceeded the speed limit by 11 to 25 km/h was 1.3 (i.e., 13% of trips). Considerably fewer (14%) had exceeded the speed limit by more than 25 km/h. As might be expected, higher levels of speeding were less common than less extreme forms of speeding.

Mobile phone use while driving was also common. Two-thirds had used a mobile phone function (e.g., receiving or sending an SMS message) during at least one of their past ten driving trips, while over half had spoken on a handheld mobile phone on at least one trip. These behaviours occurred on about 15% of driving trips. More than four in ten young people (44%) had also spoken on a hands-free mobile phone while driving. On average, talking on a hands-free mobile phone occurred on about 16% of the last 10 trips.

Another common risky driving behaviour was driving when very tired, with close to two-thirds reporting this had occurred at least once in the past ten trips. On average, young people reported driving when tired on about 15% of their most recent trips. About one in ten 23-24 year olds had been so tired that they had fallen asleep or come close to falling asleep while driving. However, such instances were very infrequent, occurring on 2% of trips.

More than one in five 23-24 year olds had driven when affected by alcohol on at least one of their ten most recent trips. However, very few had driven while under the influence of marijuana (5%), ecstasy (2%) or amphetamines (2%). The average number of trips on which young people drove when affected by alcohol or other drugs was very low (ranging from less than 1% to 4% of trips).

Only 14% reported failing to wear a seatbelt or helmet for part of a trip, and very few (5%) reported failing to wear a seatbelt or helmet altogether. Such behaviours also tended to occur very infrequently (on less than 5% of trips).

Drink-driving

Occurrence of drink-driving

Young people were asked whether they had driven when they were near or over the legal alcohol limit during the past month, and on how many days this had occurred.

Twenty per cent of all drivers (n = 193) had driven when near or over the limit in the past month. For 13%, this had occurred on one day, for 4%, on two, while 3% had engaged in this behaviour on three or more days in the past month (Table 9). The highest number of days a young person had driven when near or over the legal limit was 15.

Drink-driving behaviours of friends and romantic partners

Questions were also included about the drink-driving tendencies of friends and romantic partners (if in a romantic relationship).

Trends are shown in Table 10 and Table 11. While the majority reported that none of their friends engaged in drink-driving, a sizeable minority (39%) reported that they had a few friends who did. Very few (less than 2%) reported that most of their friends were drink-drivers.

Young drivers were asked a similar question about partners (boyfriend, girlfriend, or spouse). Close to two-thirds (65%) were in a romantic relationship, and of this group, very few thought their partner drove after having too much to drink, although this was "somewhat true" for 12% (Table 11).

Actions taken to avoid drink-driving

Young people were asked how often they made plans to avoid drinking and driving. More than two-thirds "always" planned ahead to avoid drink-driving, while a further 17% made such plans "most of the time" (Figure 2). However, almost one in ten 23-24 year-olds (9%) "rarely" or "never" made plans to avoid drink-driving.

Figure 2. Frequency of making plans to avoid drink-driving, at 23-24 years

Those who made plans to avoid drink-driving (all except those who responded "never" in Figure 2) were then asked how often they ended up drink-driving anyway (Figure 3). Approximately 1% reported drink-driving anyway on a frequent basis (e.g., "most of the time" or "always"). The vast majority (76%) never engaged in drink-driving. However, almost one-quarter had gone on to drink and drive on rare occasions.

Figure 3. Frequency of drink-driving after making plans to avoid it, at 23-24 years

All 23-24 year old study members were also asked whether they had used various strategies to avoid drink-driving within the past month. Table 12 displays the number and percentage of young people who reported having taken each action to avoid drink-driving (listed in order from most common to least common).

Note: Percentages do not add to 100% as respondents were able to select multiple options. ^a While this was not one of the response options listed for this question, a number of individuals (n = 15) indicated that they did not need to use any of the listed strategies, as they did not drink alcohol.

Most 23-24 year olds had taken at least one action to avoid drink-driving within the past month, with only 4% reporting that they had done nothing at all. The most common actions taken were to plan ahead and arrange alternative transport to one's destination, or to alter drinking habits when at a location where alcohol was served. For instance, over two-thirds had arranged for someone to drive them to their destination to avoid drink-driving, while close to 60% had taken a taxi or public transport to their destination, and about 30% found an alternative way to get there.

Furthermore, more than half had abstained from drinking alcohol within the past month to avoid drink-driving, 40% had limited the amount of alcohol they had consumed, and about a quarter had counted or spaced their drinks, or consumed more water or soft drink. Staying overnight was another common strategy (29%). Between 13% and 20% had left their car behind and found alternative transport home, and about one in ten had consumed low-alcohol beer. Only 8% had limited the amount spent on alcohol and very few (less than 5%) had tested their alcohol level using a breath-testing machine or slept in a car.

3.2 Gender differences

The young men (n = 390, 39%) and young women (n = 610, 61%) in this study significantly differed on many aspects of driving behaviour.

Licensing

Although there were no gender differences in the percentage who held a car licence, perhaps unsurprisingly, more males (13%) than females (2%) had obtained a motorbike licence.⁴ Males were also significantly more likely than females to have had their car or motorbike licence cancelled or suspended (13% compared with 3%, respectively).⁵

However, young men and women did not significantly differ in the types of licences currently held (no licence, learner's permit, probationary licence, or full licence) or the length of time they had held their licences.

Time spent driving

Young men tended to spend slightly more time behind the wheel than young women: a total of 11.5 hours (SD = 10.1) driving over the course of a week, of which 5.4 hours (SD = 6.0) was spent in weekday daytime driving. By comparison, females spent on average 10.0 hours (SD = 8.0) driving each week, and 4.6 hours (SD = 5.0) during weekday daytime hours. However, while there was a trend for differences, this did not reach the adjusted significance level.⁶

Males and females did not significantly differ in the amount of time spent driving at night (both on weekdays and weekends) or during daytime hours on weekends.

Crash involvement

No significant gender differences were found on any aspects of crash involvement (percentage involved in a crash when driving, number of crashes, crash characteristics, number fined/charged as a result of a crash).

Detection for speeding and police contact for driving-related offences

Males had been apprehended for driving-related offences significantly more often than females. Thus, males had been detected speeding 2.1 times (SD = 3.0) in their driving career on average, while females had been detected 1.2 times on average (SD = 1.6).⁷ Additionally, significantly more males (21%) than females (9%) had been in contact with the police for a driving-related offence in the past 12 months.⁸

Risky driving

Gender differences were also evident on risky driving (Figure 4). Males were more likely than females to have engaged in moderate- and high-level speeding (11-25 km/h and > 25 km/h over the limit) at least once during their ten most recent driving trips and to have driven when affected by alcohol.⁹ There were also trends for more young men than young women to have driven up to 10 km/h over the limit and to have not worn a seatbelt for part of the trip.¹⁰

Figure 4. Engagement in risky driving during previous ten trips, males and females, at 23-24 years

Females, on the other hand, were more likely to have driven when very tired on at least one of their ten most recent trips.¹¹ There was also a trend for them to have more often used a mobile phone function while driving.¹²

Drink-driving

Significantly more males than females reported drink-driving during the past month.¹³ Close to a third of young men (31%) had driven when over or near the limit, compared with 14% of young women.

While young men and young women had driven when over the limit on relatively few days in the past month, males had done so more often than females (males: M = 0.6 days, SD = 1.3; females: M = 0.2 days, SD = 0.5). ¹⁴

Significantly more males (51%) than females (34%) had friends who were drink-drivers, but females were significantly more likely to have a partner who drove after drinking (18% vs 6%).¹⁵

Gender differences were also found in the frequency with which young men and women made plans to avoid drink-driving (Figure 5).¹⁶

Figure 5. Frequency of plans being made to avoid drink-driving, males and females, at 23-24 years

Of the young people who made plans to avoid drink-driving (Figure 6), young men were more likely to drink-drive on rare occasions (28% vs 14%).¹⁷ In contrast, a higher percentage of young women "never" engaged in drink-driving after making such plans (82% vs 67%).

Figure 6. Frequency of engaging in drink-driving after making plans to avoid it, males and females, at 23-24 years

Differences were also found in the types of strategies that young men and women used to avoid drink-driving (Figure 7). Young men were more likely than young women to have: (a) reduced the amount of alcohol they had consumed, (b) counted or spaced their drinks, and (c) consumed low-alcohol beer.¹⁸ There was also a trend for them to leave their car behind and be driven home by others, or to stay overnight. Young women were more likely to report that they had abstained from drinking alcohol altogether as a strategy to avoid drink-driving.¹⁹

Figure 7. Strategies used to avoid drink-driving, males and females, at 23-24 years

3.3 Metropolitan and non-metropolitan differences

Young people's residence locality was classified into "met" and "ex-met" categories (capital city statistical division vs rest of state) using Australian Bureau of Statistics criteria. A number of significant differences were found in the driving experiences and behaviours of young people living in metropolitan (n = 682, 68% of sample) and non-metropolitan areas (n = 312, 31%).

Licensing

Young people living in metropolitan and non-metropolitan localities did not significantly differ in the types and lengths of time licences had been held, or rates of suspension or cancellation of a licence.

Time spent driving

While there were trends for young people living in metropolitan areas to spend a little longer on the road on weekdays (both during daytime and night-time hours) and more hours driving in total, these did not reach the adjusted significance level.²⁰ There were no differences in the amount of time spent driving on weekends (during daytime and night-time hours).

Crash involvement

More 23-24 year old drivers living in metropolitan areas had been involved in a crash when driving than those living in non-metropolitan areas (63% vs 52%).²¹ Metropolitan drivers had also been involved in more crashes on average (1.08 vs 0.79 crashes) and more crashes that resulted in property damage when driving alone (0.86 vs 0.55 crashes), while there was a trend for them to have been involved in these type of crashes when they were also carrying passengers.²² However, there were no significant differences on rates of crashes that resulted in injury or death, or the proportion who had been fined or charged as a result of a crash.

Detection for speeding and police contact for driving-related offences

There were no differences between young people from metropolitan and non-metropolitan areas on the number of times they had been detected speeding, or had police contact for driving-related offences.

Risky driving

Several differences were found between metropolitan and non-metropolitan drivers in their engagement in risky driving. A higher percentage of metropolitan drivers had talked on a hands-free mobile while driving on at least one of their ten most recent trips (49% vs 31%), whereas non-metropolitan drivers were more likely to have not worn a seatbelt or helmet for a part of a recent trip (18% vs 11%). There was also a similar trend for differences on failure to wear a seatbelt for the whole of a trip.²³

Drink-driving

Similar numbers of 23-24 year olds from metropolitan and non-metropolitan areas had engaged in drink-driving at least once in the past month. There was a trend for young people from non-metropolitan areas to drink-drive on more days than their metropolitan counterparts (non-metropolitan: M = 0.5 days, SD = 1.2; metropolitan: M = 0.3 days, SD = 0.7), but this did not reach the adjusted significance level.²⁴ There was also a trend for more young drivers living in non-metropolitan areas to have friends who engaged in drink-driving (46% vs 38%), but again, this did not reach the adjusted significance level.²⁵ Metropolitan and non-metropolitan drivers did not significantly differ in their likelihood of having a partner who drove after having too much to drink.

No significant differences were found between metropolitan and non-metropolitan young drivers on making plans to avoid drink-driving, or the frequency of drink-driving after making plans to avoid doing so. However, a number of significant differences were found in the types of strategies used to avoid drink-driving. As shown in Figure 8, non-metropolitan drivers were more likely to report that, to avoid drink-driving, they had left their car behind and (a) been driven home, (b) taken a taxi or public transport, and/or (c) found another way home.²⁶ In contrast, metropolitan drivers were more likely to report that they had (a) reduced the amount of alcohol they had consumed, (b) counted or spaced their drinks, or (c) consumed more water or soft drink.²⁷ Thus, young people from metropolitan areas were more likely to change their drinking habits to avoid drink-driving, while their counterparts from non-metropolitan areas were more likely to leave their car behind and arrange another way to get home.

Figure 8. Strategies used to avoid drink-driving, metropolitan and non-metropolitan young drivers, at 23-24 years

3.4 Occupational status differences

The ANU-4 Occupation Status scale (Jones & McMillan, 2001) was used to rank young people's occupations in order of relative prestige. The scale assigns a score, ranging from 0 to 100, to an individual's occupation. In devising the ranking, the ANU-4 takes into account the occupation's ranking on the Australian Bureau of Statistics' Classification of Occupations, and relationships between the occupation and Australian population educational attainment and income levels.

Young people were divided into three groups on the basis of their occupation status. These were:

• a low occupational status group (n = 220, the lowest 25% of the ATP sample in terms of occupational status);
• an average occupational status group (n = 449, the middle 51% of the ATP sample in terms of the status of their occupation); and
• a high occupational status group (n = 212, the highest 24% of the ATP sample in terms of their occupational status).

Licensing

Young people employed in low-, average- and high-status occupations did not significantly differ in the types and lengths of time licences had been held, or whether a licence had been cancelled or suspended.

Time spent driving

The three occupational status groups did not significantly differ in the amount of time spent driving each week (in total, during weekdays and weekends, or during daytime or night-time hours).

Crash involvement

Young people employed in low-, average- and high-status occupations did not significantly differ in their likelihood of involvement in a crash, the number and types of crashes experienced, or their receipt of a fine or charge as a result of a crash.

Detection for speeding and police contact for driving-related offences

No significant differences were found between the three occupational status groups in the number of times they had been detected speeding, or their level of police contact for driving-related offences.

Risky driving

A similar proportion of young people employed in low-, average- and high-status occupations had engaged in each type of risky driving behaviour.

Drink-driving

Young drivers in the low, average and high occupational status groups did not significantly differ in their likelihood of engaging in drink-driving, or the frequency with which they had driven when near or over the alcohol limit during the past month.

There were no significant differences in the drink-driving behaviour of their friends and romantic partners.

There were also no significant differences in how often young people in the three groups made plans to avoid drink-driving. However, those in the high occupational status group were less likely to engage in drink-driving after making such plans than other drivers (Figure 9).²⁸

Figure 9. Frequency of drink-driving after making plans to avoid it, low-, average- and high-status occupations, at 23-24 years

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There were trends for differences in the types of strategies used to avoid drink-driving. For example, those in the low occupational status group were more likely to limit the amount of money spent on alcohol (low: 12%; average: 7%; high: 7%), and less likely to plan ahead and take a taxi or public transport to their destination (low: 52%; average: 63%; high: 64%), but these did not reach the adjusted significance level.²⁹

3.5 Education level differences

Young people were classified into groups on the basis of the highest level of education they had completed. These were:

• secondary (n = 296, 30%): those who had completed some or all of their secondary education, but not engaged in any post-secondary education;
• other post-secondary (n = 258, 26%): those who had completed some form of post-secondary education other than a university degree (e.g., a TAFE diploma/certificate, an apprenticeship); and
• university (n = 440, 44%): those who had completed a university degree.

Comparisons of these groups revealed a number of significant differences.

Licensing

Some significant differences in the licensing status of the three educational attainment groups were found. As shown in Figure 10, fewer of those with secondary education held a driver's licence (90%) and more held a learner's permit (6%) than those in the other post-secondary group (98% of whom held a driver's licence and 1% a learner's permit).³⁰

Figure 10. Type of licence held by secondary, other post-secondary and university groups, at 23-24 years

Young people with a university qualification were less likely to have had their licence cancelled or suspended than those in the other post-secondary group (secondary: 9%; other post-secondary: 10%; university: 3%).³¹

Time spent driving

The group who had completed other post-secondary education spent close to 12 hours a week driving on average (M = 11.8, SD = 9.9), whereas those in the secondary education group spent about ten-and-a-half hours driving (M = 10.4, SD = 8.7), and those with a university degree, almost 10 hours per week behind the wheel (M = 9.9, SD = 8.4). While this represents a trend for differences, these did not reach the adjusted significance level.³² The three educational attainment groups did not significantly differ in the amount of time they spent driving at different times of the day (daytime, night-time) or week (weekdays, weekends).

Crash involvement

The three groups did not significantly differ in whether or not they had been involved in a crash, the total number of crashes experienced, or the type of property crashes experienced. However, there was a trend for those in the other post-secondary group to have been involved in more injury crashes when driving alone (M = 0.09, SD = 0.4) than those in the secondary (M = 0.03, SD = 0.2) and university (M = 0.03, SD = 0.2) groups (but note that rates of these types of crash were very low overall).³³

Young people with a secondary education had more often been fined or charged as a result of a crash than those with a university degree (secondary: M = 0.07, SD = 0.3; other post-secondary: M = 0.03, SD = 0.2; university: M = 0.01; SD = 0.1), although again it should be noted that this very rarely occurred in the ATP sample.³⁴

Detection for speeding and police contact for driving-related offences

Young people with a university degree had been detected speeding on fewer occasions (M = 1.2, SD = 1.6) than those with secondary (M = 1.7, SD = 2.1) and other post-secondary education (M = 1.8, SD = 3.2).³⁵

While those with a university degree were somewhat less likely to have been in contact with police for a driving-related offence than other drivers (11% vs 14% of the secondary and 18% of the other post-secondary groups), the differences found did not reach the adjusted significance level.³⁶

Risky driving

The three educational attainment groups did not significantly differ on their engagement in different risky driving behaviours, although there were some trends for differences (e.g., those with a university degree had less often been involved in moderate-level speeding (11-25 km/h over) or driven without a seatbelt or helmet for all or part of a recent driving trip).³⁷

Drink-driving

There were no differences between the secondary, other post-secondary and university groups in the proportion of young people who had engaged in drink-driving, or the number of days on which drink-driving had occurred.

Young people with a university degree were significantly less likely than those with a secondary education to have friends who engaged in drink-driving (secondary: 48%; other post-secondary: 43%; university: 35%).³⁸ However, the three groups did not significantly differ on the proportion whose partners were drink-drivers.

There were also no differences in the frequency with which the three groups made plans to avoid drink-driving. However, of the subset of young people who made plans to avoid drink-driving, fewer of the university group ended up drink-driving anyway (Figure 11).³⁹

Figure 11. Frequency of drink-driving after making plans to avoid it, secondary, other post-secondary and university groups, at 23-24 years

Several significant differences were found in the strategies that young people with differing levels of education used to avoid drink-driving (Figure 12). Those in the other post-secondary group were more likely to have abstained from drinking,⁴⁰ while young people with a university degree were significantly more likely than those in the secondary group to have planned ahead and been driven to their destination or taken a taxi or public transport, as a strategy to avoid drink-driving.⁴¹ Some other trends were also noted (e.g., those with a secondary education were more likely than those with a university degree to use a breath-testing machine or sleep in their car,⁴² and the other post-secondary group were more likely to drink water or soft drink than the secondary group).

Figure 12. Actions taken to avoid drink-driving, secondary, other post-secondary and university groups, at 23-24 years

4. Consistency of driving behaviour over time

This next chapter focuses on an important issue - the stability of driving behaviour over the early years of young people's driving careers. Do young people maintain the same tendencies to drive safely or riskily, or do they change in style as they gain maturity and more years of driving experience?

The scant research available suggests that risky driving tends to decrease as young people make the transition from adolescence to adulthood (Bingham, Shope, Zakrajsek, & Raghunathan, 2008; Jessor, Turbin, & Costa, 1997). For instance, Jessor and colleagues noted a decline in levels of risky driving among young drivers between the ages of 18 and 25 years. Similarly, Begg and Langley (2001) reported a decrease in the prevalence of almost all types of risky driving between the ages of 21 and 26, although this decrease was only apparent among males.

Explanations of this trend point to the developmental changes that typically occur during early adulthood (Bingham et al., 2008; Jessor et al., 1997). The transition from adolescence to adulthood is generally a time of considerable change in multiple aspects of life. For many, this period witnesses the transition from school to employment and/or further education, a move out of the parental home, as well as the development of intimate relationships, marriage and parenthood. Some argue that adolescents engage in problem behaviours such as risky driving to gain adult-like status (Jessor et al., 1997). The taking on of adult occupational, marital and parental roles has been linked to decreased involvement in problem behaviours (Jessor et al., 1997). For example, Bingham and colleagues found that both the degree and frequency of risky driving decreased with increasing levels of psychosocial maturity (as reflected by the adoption of adult roles and completion of developmental tasks associated with becoming an adult). It has also been suggested that a decrease in immature characteristics such as sensation-seeking and self-centredness that may underlie risk-taking contributes to the decline in problem behaviour often seen during early adulthood (Arnett, 2001).

Another explanation points to the benefits that increased experience on the road brings to driving skills. Some forms of risky driving, such as unsafe lane changes or following too closely, may not be intentional, but instead reflect inexperience or inadequate driving skills. It is possible that young people drive in a less risky manner as they grow older because their driving skills and appreciation of the dangers of risky driving improve with experience (Bingham et al., 2008). On the other hand, greater confidence could also lead to an increase over time in risky driving among young people who were initially safe drivers.

Finally, recent research suggests that brain development continues through adolescence and early adulthood, with capacities associated with impulse control, decision-making, planning and judgement being the last to evolve (Giedd, 2004; Sowell, Thompson, Holmes, Jernigan, & Toga, 1999). Hence, it is possible that cognitive maturation may also account for the decline in risk-taking observed over this period.

Information collected at 19-20 and 23-24 years of age on young people's engagement in a range of driving practices is used here to investigate the stability of driving tendencies over this age period. Two main aspects are explored: (a) the stability of particular types of risky driving, and (b) the continuity of young people's overall propensity to engage in risky driving between 19-20 and 23-24 years.

Four main questions are addressed:

• Did rates of risky driving increase, decrease or remain the same across the ATP sample between the ages of 19-20 and 23-24?
• Were the same individuals engaging in specific types of risky driving at 19-20 and 23-24 years (e.g., speeding, failure to wear seatbelts, driving under the influence of alcohol or other drugs)?
• How similar were the driving profiles of 19-20 and 23-24 year olds who were identified as high-level risky drivers?
• Did young people identified as low-, moderate- and high-level risky drivers at 19-20 years show similar driving tendencies at 23-24 years?

4.1 Stability of different types of risky driving among the sample

We were first interested in looking at whether or not there had been a change in the percentage of young people who engaged in different types of risky driving at 19-20 and 23-24 years in this sample of young Australians. As a wider range of risky driving types was measured at age 23-24 than at 19-20, only those behaviours that were assessed at both time points were included in these comparisons.

Figure 13 shows the rates of occurrence of each form of risky driving at 19-20 and 23-24 years for this sample (risky driving was defined as the percentage who had engaged in the risky driving practice on at least one of their past ten trips).

Figure 13. Engagement in risky driving during previous ten trips, at 19-20 and 23-24 years

As this figure shows, the percentage of young people who engaged in moderate-level speeding (between 11 and 25 km/h over the limit) decreased somewhat between the ages of 19-20 and 23-24 years (from 49% to 45%), as did the percentage who reported high-level speeding (driving at more than 25 km/h above the limit; this decreased from 19% to 14%). Driving without a seatbelt (or helmet) for all of a trip, while uncommon in this sample, also dropped, with 9% reporting this behaviour at age 19-20, compared with 5% at 23-24 years.

Rates of most other risky driving behaviours (e.g., speeding up to 10 km/h over the limit, failure to wear a seatbelt (or helmet) for part of a recent trip, driving when very tired, and driving when affected by an illegal drug) remained fairly constant among the sample over this time period. However, the percentage who drove when affected by alcohol increased markedly from 14% at 19-20 years to 23% at 23-24 years.

As well as looking at whether there had been a change in the percentage who had engaged in differing types of risky driving at ages 19-20 and 23-24, we were also interested in determining whether there had been a change in how frequently risky driving practices occurred. Figure 14 shows the average number of trips on which this sample of

Figure 14. Frequency of risky driving behaviours, at 19-20 and 23-24 years

As illustrated in Figure 14, young people tended to engage in speeding slightly less often at age 23-24 than they did at age 19-20. For instance, the average number of trips during which young people engaged in low-level speeding decreased from 4.1 (or 41%) of their past ten trips at age 19-20 to 3.7 (or 37%) of their past ten trips at age 23-24; and moderate-level speeding decreased from 1.6 (16%) of trips to 1.3 (13%) of trips. The frequency of all other types of risky driving was similar at the two ages (driving when very tired, not wearing a seatbelt or helmet for part or all of a trip, or driving when affected by alcohol or illegal drugs).

4.2 Stability of different types of risky driving among individuals

We also sought to investigate (a) whether the same individuals who engaged in risky driving practices at 19-20 years were still doing so at 23-24 years, and (b) how often individuals who engaged in risky driving at 19-20 did so at 23-24 years.

To answer these questions, young people were divided into groups according to whether or not they had engaged in a particular form of risky driving in their last 10 trips at 19-20 years of age. Their risky driving profile at 23-24 years on five key indicators was then examined: high-level speeding, driving without a seatbelt or helmet, driving when fatigued on multiple occasions, driving when affected by alcohol, and driving when affected by an illegal drug. The criteria used to form the five separate groups and the numbers in each group are summarised in Table 13.

Note: ^a Due to the high prevalence of fatigued driving in the sample, this criterion differentiates those who drove when very tired on multiple occasions from those who only once or never drove when very tired.

Most of the young people who did not engage in a particular risky driving practice at 19-20 years also did not engage in this behaviour at age 23-24 (Figure 15). This was particularly true for driving when affected by an illegal drug, high-level speeding and driving without a seatbelt or helmet, with 92% to 96% of young adults who refrained from these behaviours at 19-20 years continuing to do so at 23-24. However, 30% of those who had not driven when very tired at 19-20 did so at 23-24 years, and 18% of those who had not driven when affected by alcohol at the younger age did so at the older age.

Figure 15. Engagement in risky driving behaviours at 23-24 years, by whether engaged in by the same individuals at 19-20 years

There was much less stability in the later driving behaviour of those who had engaged in each type of risky driving at 19-20 years (Figure 15). For instance, the majority of individuals who had at age 19-20 driven when affected by an illegal drug, engaged in high-level speeding or who had driven without a seatbelt no longer did so at 23-24 years. About half of those who drove when affected by alcohol and/or drove when very tired at age 19-20, continued to do so four years on.

Furthermore, those who engaged in risky driving at 19-20 years did so less frequently at 23-24 years than at 19-20 (Figure 16). For example, high-level speeders had driven more than 25 km/h above the legal limit on 2.6 (or 26%) of their past ten trips at 19-20 years, in contrast to only 1.0 (10%) of their ten most recent trips at 23-24 years. Similarly, among those who had driven when very tired at 19-20 years, this had occurred on 34% of their recent trips at 19-20 years, compared with 21% of their ten most recent trips at 23-24 years. Trends were similar for failure to wear a seatbelt or helmet, and driving when affected by alcohol or an illegal drug.

Figure 16. Frequency of engagement in risky driving behaviours by the same individuals, at 19-20 and 23-24 years

4.3 Similarity of 19-20 year old and 23-24 year old risky drivers

The previous sections investigated the persistence of driving tendencies over time. Section 4.1 showed that across the whole sample there was a modest decrease of 3-5% in three of the eight types of risky driving examined, a sizable increase in a fourth type and minimal change in the other four indicators. Section 4.2 showed that individuals who did not engage in a particular form of risky driving at 19-20 years were generally unlikely to do so at 23-24, while risky driving had greatly decreased at 23-24 years among those who had engaged in a risky driving practice(s) at 19-20 years.

Nevertheless, risky driving remained quite prevalent at 23-24 years. This next section looks at whether groups of individuals who were identified as risky drivers at 23-24 years showed similar propensities for risky driving as groups of individuals who were identified as risky drivers at 19-20 years. To answer this question, five separate risky driving sub-groups were identified at 23-24 years, using the same classifications as at 19-20 years. The sub-groups identified at 23-24 years are shown in Table 14.

Note: ^a Due to the high prevalence of fatigued driving in the sample, this criterion differentiates those who drove when very tired on multiple occasions from those who only once or never drove when very tired.

We then compared the levels of risky driving shown by the 23-24 year old risky driving sub-groups at the age at which they were identified as risky drivers (i.e., at 23-24 years) to the levels of risky driving of the 19-20 year old risky driving sub-groups at the age at which they were identified as risky drivers (i.e., at 19-20 years).

Figure 17 shows the trends for these comparisons. For example, with regard to speeding, the group of young people who engaged in high-level speeding at 19-20 years had done so on about 26% of recent trips (when 19-20 years old). By comparison, the group of young people who engaged in high-level speeding at 23-24 years had done so on 22% of their past 10 trips (at 23-24 years of age).

Figure 17. Frequency of risky driving behaviours, 19-20 and 23-24 year old risky driving sub-groups

The frequency of most risky driving behaviours was similar across the 19-20 and 23-24 year old risky driving groups. For instance, young adults who had driven when affected by alcohol at age 19-20 had done so as often as those who engaged in this behaviour at age 23-24 years (an average of 16% of trips at both ages).

Nevertheless, one difference was found: the group of 23-24 year olds who engaged in high-level speeding did so slightly less often than their 19-20 year old counterparts (26% trips at 19-20 years vs 22% trips at 23-24 years).

4.4 Consistency of patterns of risky driving from 19-20 to 23-24 years

In the first In the Driver's Seat report, groups exhibiting differing levels of risky driving at 19-20 years were identified using cluster analysis (see Smart & Vassallo, 2005, for further details). In brief, three groups of drivers were identified: (a) a large group that was lowest on all types of risky driving - the low-level risky driving group (n = 675, 64% of the sample); (b) a small group that was highest on all indicators of risky driving, particularly speeding - the high-level risky driving group (n = 74, 7% of the sample); and (c) a group with rates of risky driving that were intermediate to the low and high groups - the moderate-level risky driving group (n = 306, 29% of the sample). These groups differed significantly in gender composition (with more females than males in the low-level group and more males than females in the high-level group), and in their experiences of crashes and being detected for speeding (the high-level group had experienced more crashes and were more often detected speeding). Looking back in time, the high-level group could be differentiated from the other groups from mid- to late childhood on a range of personal, family, peer and school progress characteristics.

This next section follows forward the risky driving tendencies of these three groups. Two approaches are taken:

• the low-, moderate- and high-level risky driving groups⁴³ are compared on separate indicators of risky driving at 19-20 and 23-24 years to investigate whether their risky driving propensities have increased, decreased or remained similar over this time period; and
• cluster groups displaying differing levels of risky driving at 23-24 years are identified, and the 19-20 year old clusters' placement in these groups is probed.

Profiles of risky driving clusters 4 years later

Figures 18 to 20 display the profiles of the three risky driving groups identified at 19-20 years on various aspects of risky driving four years later (at 23-24 years). In these figures, the average number of trips during which young people had engaged in each type of risky driving behaviour at 19-20 years are compared to the average number of trips in which the behaviour had occurred at 23-24 years. Figure 18 shows trends for the low-level risky driving group, Figure 19 the moderate-level risky driving group, and Figure 20 the high-level risky driving group. As a larger number of items were included at 23-24 years than at 19-20, comparison data is not available for all items.

Looking first at the low-level risky driving group (Figure 18), there was a trend for young people in this group to engage in most types of risky driving more often at age 23-24 than they had at 19-20. However, with the exception of low- and moderate-level speeding and fatigued driving, these increases were very small. Rates of most forms of risky driving were generally very low at 23-24 years (generally occurring on less than 5% of trips), with the exceptions of low-level speeding (29% of trips), driving when fatigued, and all types of mobile phone use when driving, which on average occurred on about 10% to 15% of trips.

Figure 18. Frequency of risky driving behaviours, low-level risky driving group, at 19-20 and 23-24 years

Comparison of the profiles of the moderate-level risky driving group at 19-20 and 23-24 years showed a reduction in speeding (particularly in the low- and moderate-level categories) and fatigued driving over this time period (Figure 19). There were only small changes in the frequency of other types of risky driving behaviour over this time. Nevertheless, at 23-24 years, this group had, on average, been involved in low-level speeding on about 50% of recent trips, and in moderate-level speeding, driving when fatigued and mobile phone use on approximately 20% of recent trips. All other type of risky driving had a very low occurrence.

Figure 19. Frequency of risky driving behaviours, moderate-level risky driving group, at 19-20 and 23-24 years

There was a marked reduction in speeding (at all levels) and driving when very tired between the ages of 19-20 and 23-24 years for the high-level risky driving group (Figure 20). However, there was little change in the frequency of drink-driving, driving when affected by illegal drugs, and driving without a seatbelt or helmet (for all or part of a trip) among this group. Risky driving was still quite prevalent among this group at 23-24 years, with low-level speeding occurring on about two-thirds of recent trips; moderate-level speeding on 40% of recent trips; using a mobile function on 30% of trips; and high-level speeding, driving when fatigued and other mobile phone use on close to 20% of trips.

Figure 20. Frequency of risky driving behaviours, high-level risky driving group, at 19-20 and 23-24 years

To sum up, while there was a decrease in levels of risky driving among the high- and moderate-level risky driving groups from 19-20 to 23-24 years, these groups' levels of risky driving were still noticeably higher than the low-level risky driving group, who showed a slight increase in risky driving from 19-20 to 23-24 years.

Stability of cluster group membership from 19-20 to 23-24 years

The second approach taken was to investigate whether cluster group members identified at 19-20 years would continue to be classified in a similar way at 23-24 years of age. To investigate this question, cluster analysis was used to identify groups with differing levels of risky driving at 23-24 years, as had been done at 19-20 years.⁴⁴

The analyses suggested that a solution of between two and five clusters provided the best representation of risky driving patterns in the sample (see Table 15 for a description of these solutions).

For all solutions of three or more clusters, low- and moderate-level groups consistently emerged. In the four- and five-cluster solutions, differentiation of high-level risky drivers occurred. For example, a small group who frequently drove without a seatbelt or helmet was identified (cluster groups 4b and 5b).

While all solutions were meaningful, the three-cluster solution was considered the most appropriate for future analyses. The small number of cases in some of the clusters identified in the four- and five-cluster solutions (group sizes of 9, 16 and 19) precluded their use in further analyses, while the two-cluster solution did not provide sufficient differentiation.

As shown in Figure 21, the three-cluster groups significantly differed in their frequency of engagement in risky driving behaviours at 23-24 years.⁴⁵

Figure 21. Frequency of risky driving behaviours, three-cluster groups, at 23-24 years

As found at 19-20 years, there were significant gender differences (Table 16),⁴⁶ with more young men than young women in the high-level risky driving group and far fewer young men than young women in the low-level risky driving group.

Furthermore, consistent with the findings at 19-20 years, the groups significantly differed on the amount of police contact for driving-related offences⁴⁷ and number of times they were detected speeding,⁴⁸ with the high-level risky driving group experiencing the highest rates of apprehension for a driving offence. In terms of crash involvement, the high- and moderate-level groups had almost identical rates, which were higher than the low-level group, although only the moderate-level group significantly differed from the low-level group on this aspect (perhaps because the size of the high-level group, n = 57, was too small to detect significant differences).⁴⁹

It also should be noted that there was considerable variability in the number of crashes and speeding violations reported by young people within each of the groups (as indicated by the large standard deviations). This within-group variability was particularly notable in the high-level risky driving group.

Next we examined the degree of commonality between the cluster groups identified at age 19-20 and those identified at 23-24 years, to determine whether the same individuals who engaged in low-, moderate- or high-level risky driving at 19-20 years were still doing so at 23-24 years.

This comparison revealed a great deal of stability in the low-level group, with three-quarters (76%) of those classified as low-level risky drivers at 19-20 being classified in the same category at 23-24 years (Table 17). Of the remaining quarter whose risky driving behaviour increased over this time period, almost all were classified as moderate-level risky drivers at 23-24 years. Very few (2%) changed from being low-level risky drivers at 19-20 years to high-level risky drivers at 23-24.

The moderate- and high-level groups were less stable, with the majority of individuals in these clusters at 19-20 years being classified as less problematic at 23-24 (52% of the moderate-level group and 72% of the high-level group showed improvement). However, some had become more risky. About 11% of those identified as moderate-level risky drivers at 19-20 years showed an increase in their risky driving behaviour between 19-20 and 23-24 years.

It is interesting to note that while it was extremely uncommon for a low-level risky driver at age 19-20 to become a high-level risky driver at 23-24, a change in the opposite direction was not as unusual, with almost a quarter of those classified as high-level risky drivers at 19-20 years showing low levels at 23-24 years.

Looking next at trends across the entire sample, cluster group position remained stable for the majority, with 62% being classified as displaying the same pattern of risky driving (low-, moderate- or high-level) at age 23-24 as they had at 19-20. However, almost one in five (19%) showed an increase in risky driving between the ages of 19-20 and 23-24, while a similar proportion (20%) showed a decrease in risky driving behaviour over this time period.

Of particular interest was the progress of the high-level group. It had been hoped to compare those who had improved with those who remained stable to explore whether particular characteristics or experiences may have been instrumental in facilitating change. However, the small numbers precluded these additional analyses.

4.5 Discussion and implications

In order to determine the stability of risky driving behaviour over time, four sets of analyses were undertaken.

The first set of analyses focused on the whole sample of young Australians to determine whether there had been a general change in rates of different types of risky driving from 19-20 to 23-24 years. A modest decrease of 3-5% was found for three of the eight types of risky driving examined (moderate- and high-level speeding, failure to wear a seatbelt or helmet for all of a trip), a sizable increase in a fourth type (driving when affected by alcohol), and minimal change in the other four indicators.

The second set focused on risky driving sub-groups, and looked at the stability of specific types of risky driving over 4 years (e.g., speeding, driving when fatigued, driving when affected by alcohol). Individuals who did not engage in these types of risky driving at 19-20 years were very unlikely to do so at 23-24 years. In addition, among those who had been involved in these types of risky driving at 19-20 years, the occurrence of the risky driving practice had greatly decreased by 23-24 years.

The third set investigated whether 19-20 year old risky drivers showed similar patterns of risky driving as 23-24 year old risky drivers. Rates of most forms of risky driving were relatively similar across the two age groups.

The final set of analyses followed forward the high-, moderate- and low-level risky driving cluster groups identified at 19-20 years (classified using all risky driving indicators simultaneously) to determine whether they would again be classified as high-, moderate- or low-level risky drivers at 23-24 years. A high degree of stability was found for the low-level group, with three-quarters being classified similarly at the later age. However, less continuity was found for the moderate- and high-level groups, with the majority of individuals from these groups found to be in less problematic clusters at 23-24 years.

Some conclusions and implications that may be drawn from the findings are presented below.

A safe approach to driving was highly persistent

An important finding emerging from this research is that the majority of young people who did not engage in risky driving at 19-20 years continued to refrain from unsafe driving practices four years on. For instance, 92% to 96% of individuals who did not drive when affected by illegal drugs, speed at high levels or drive without a seatbelt at age 19-20, continued to not engage in these behaviours at 23-24. Similarly, three-quarters of young people classified as low-level risky drivers at 19-20 years continued to exhibit a pattern of low-level risky driving four years later. While some low-level risky drivers exhibited an increase in risky driving over this period, for the majority, the change was not large. Only 2% progressed from little or no engagement in risky driving at age 19-20 to high levels of unsafe driving at 23-24. Thus, the possibility that increasing experience on the road might encourage initially safe young drivers to subsequently engage in risky driving was not supported by these findings.

These findings reinforce the value of current road safety initiatives aimed at discouraging risky driving among novice drivers, as they suggest that avoidance of risky driving during the early years of a person's driving career is very likely to persist and be linked to safe driving practices at a later age. Given that risky driving is associated with a heightened risk of crash involvement (Crettenden & Drummond, 1994; Williams, 1998) and engagement in a range of other risky or problematic behaviours such as antisocial behaviour and substance use (Vassallo et al., 2008; Williams, 1998), such preventative initiatives have clearly been of great value.

It will be important to continue tracking the driving behaviour of these low-level risky drivers in order to confirm that their pattern of low-level risky driving is maintained, and hence that early avoidance of risky driving is highly persistent.

Risky driving declined among many high-level risky drivers

Another encouraging finding was that engagement in risky driving did not persist for many young risky drivers. For instance, the majority of individuals who engaged in high-level speeding, driving when affected by illegal drugs, or who failed to wear a seatbelt or helmet when driving at 19-20 years no longer engaged in these behaviours at 23-24 years. Additionally, the majority of young people identified as being in the moderate- and high-level risky driving clusters at 19-20 years showed a reduction in risky driving by 23-24 years. For a small number, this improvement was quite marked, with one in ten high-level risky drivers showing low levels of risky driving by 23-24 years. Due to the small numbers available for analysis, it was not possible to undertake further analyses to identify factors associated with persistence or improvement, but this is clearly an important next step for research.

These findings highlight the fact that young problem drivers are not destined to continue posing a road safety risk as they grow older. Rather, it would appear that improvement is not only possible, but common. This finding is supported by past research showing a decline in problem behaviours as young people mature and assume adult roles (Bingham et al., 2008; Jessor et al., 1997). Nevertheless, once again, it will be important to continue to follow the progress of the high-level risky driving group over the coming years to determine whether they maintain this improvement.

While it may seem important to concentrate road safety efforts on young drivers who exhibit a stable pattern of high-level risky driving behaviour, we do not yet have the tools to reliably identify those who persist and those who improve, and the factors that facilitate positive change. Further, while risky driving may be temporary, it still has the potential to result in considerable personal, social and economic costs to individuals, families and the wider community, and to have a long-term impact on young people's life trajectories. Thus, it will remain essential to continue targeting risky driving among young novice drivers, to take them out of known high-risk situations at a time when they are building their driving skills (for example, via publicity programs highlighting the dangers of peers as passengers, or the restrictions imposed by the Victorian graduated licence system).

Risky driving was a continuing concern for a small number in their mid-20s

For a small number, risky driving continued to be a concern in their mid-20s. For example, over a quarter of high-level risky drivers identified at age 19-20 (albeit less than 2% of the sample) continued to exhibit risky driving tendencies four years on. Another group of concern were the small number who engaged in low levels of risky driving at 19-20 years and progressed to frequent engagement in risky driving in their mid-20s (2% of low-level risky drivers, 1% of the sample). Both groups would seem to pose major road safety risks, and hence further research focusing on these young drivers would appear warranted.

Questions that could be addressed include:

• What personal, social or environmental factors differentiate persistently high-level risky drivers from other drivers, especially those who cease engaging in such behaviour?
• What factors may have caused the small group who progressed to high-level risky driving at age 23-24 to "buck the trend" and start taking risks on the road at a time when many others had or were desisting from this type of behaviour?
• How entrenched is this behaviour? If we were to look at the driving behaviour of these two groups in another four years' time, would they continue to engage in high levels of risky driving?

As noted earlier, due to the small number of young people who displayed these patterns of driving within our study, the first two questions are beyond the scope of this report. Such knowledge would be extremely helpful in informing intervention and prevention efforts targeted at these high-level risky driving groups. Hence, further longitudinal research, employing larger samples, is needed in order to better understand the attributes and experiences of these individuals, and the long-term stability of their driving patterns.

There were changes in rates of risky driving over time

Between the ages of 19-20 and 23-24, there was a marked decrease in rates of speeding and driving without a seatbelt among the ATP sample. These findings are heartening, given the strong links between excessive speeding and crash involvement (Clarke et al., 2002; Engström, Gregersen, Hernetkoski, Keskinen, & Nyberg, 2003) and non-seatbelt use and risk of injury or death in the event of a collision (Data Analysis Australia, 2000).

However, troublingly, rates of other types of risky driving either increased or remained stable over this time period. Driving when fatigued remained very prevalent, and had not dropped in incidence (almost two-thirds of the sample at both ages reported this had occurred in their last 10 trips). Furthermore, the number of young people who drove when affected by alcohol increased markedly from 14% at 19-20 years to 23% at 23-24 years.

The increase in drink-driving over this period may reflect differences in licence restrictions at the two ages. For instance, at 19-20 years, all of the drivers in the study held probationary licences or learner's permits, and thus were required to have a zero blood alcohol content (BAC) level when driving. Hence, it is not surprising that rates of drink-driving were relatively low at this age. However, at 23-24, when rates of drink-driving were noticeably higher, most young drivers held full licences and thus were permitted to have a low level of alcohol in their system when driving (the legal BAC level in Victoria is 0.05 g/100ml). Hence, it is likely that the more stringent restrictions imposed on less experienced drivers had a stronger deterrent effect on drink-driving than those placed on fully licensed drivers, possibly explaining this increase.

Nonetheless, the increase in prevalence of drink-driving between 19-20 and 23-24 years reported here is still of concern, and parallels the higher rates of crashes associated with drink-driving and convictions for drink-driving found at this age in the accident and enforcement statistics for the state of Victoria. For example, of the 50 drivers and motorcyclists killed in Victoria in 2008 who had a BAC at 0.05 g/100ml or over, 82% were males, 34% were between 21 and 29 years of age, 20% were aged between 30 and 39 years, 28% were aged over 40, and the remaining 18% were 20 years of age or younger (Transport Accident Commission [TAC], 2009a).

The prevention of drink-driving has been the focus of a wide range of road safety initiatives in Australia in recent years. However, despite these efforts, it would appear that these campaigns and programs are not reaching all young drivers. Further efforts are needed to discourage young people from engaging in this potentially lethal practice, as is better understanding of why current initiatives targeted at drink-driving are not connecting with some young drivers, and how this group may be better targeted.

Risky drivers at both ages were equally problematic

While there were signs that a modest reduction in engagement in risky driving from 19-20 to 23-24 years had occurred as shown by the overall sample trends; when young people did engage in risky driving at the older age, they did so almost as frequently as their younger counterparts. Thus, there was little support for the notion that with increasing age, those who engage in risky driving would do so at lower intensities than younger drivers. The driving tendencies of risky drivers were equally problematic at both ages. This suggests that risky driving is as serious an issue (when present) in the mid-20s as in the late teens, and points to the importance of sustaining road safety efforts into the twenties. While drink-driving is rightly highlighted as a particular problem for young people in their mid-20s, other forms of risky driving are also salient and merit attention.

Overall, levels of risky driving remained fairly stable

As noted above, there were signs that a small decline in risky driving may have been occurring among this sample of young Australians, with decreases of 3-5% on three of the eight types of risky driving examined (i.e., moderate- and high-level speeding, and failure to wear a seatbelt or helmet for all of a trip). However, there was a sizable increase in drink-driving, and virtually no change in the remaining four indicators. Thus, to the extent that there was change, this was modest rather than dramatic. While an improvement was evident in the subsequent driving careers of many individuals who had been high- or moderate-level risky drivers at 19-20 years, the general sample trends suggested only a modest degree of change. Overall, then, these findings suggest a fair degree of stability in risky driving over the four-year period examined.

These findings are somewhat at odds with past research, which suggests that risky driving typically decreases over early adulthood (Bingham et al., 2008; Jessor et al., 1997). A number of explanations are possible, although we have no direct evidence that can speak to these possibilities.

Measurement differences may have contributed. The indicators of risky driving used in the current study (e.g., speeding, drink-driving, driving when affected by illegal drugs, fatigued driving and non-use of seatbelts) differed from those used in several other studies, which have tended to focus on behaviours such as tailgating, unsafe passing and running red lights or stops signs. The young people in the ATP study may be at a different stage in their driving careers to those in other international studies. Our young people have been able to hold licences from 18 years of age, whereas those in studies from other countries have often held licences from an earlier age. There may also be differences due to studies being conducted in different time periods: our study shows trends for 2006-2007, while some other studies report trends from the 1990s or earlier. Cultural effects may also be present, with different attitudes towards risky driving, values concerning appropriate behaviour on the road and tolerance for acts such as drink-driving influencing societal trends in risky driving among young people.

The relative stability found emphasises once again the need for road safety efforts to continue targeting young people beyond the first years of their driving careers. Broad-based initiatives targeting all young drivers (e.g., community campaigns, police and enforcement efforts) may be beneficial in reducing the general level of risky driving among young people.

Conclusions

In summary, this chapter examined the stability of driving behaviour over the early adult years. Two main approaches were taken. The first involved examining the stability of particular forms of risky driving between the ages of 19-20 and 23-24, while the second looked at the constancy of young people's propensities to engage in multiple forms of risky driving across this time period.

While modest declines in some forms of risky driving were noted, and some individuals showed a decrease in their risky driving tendencies over this time period, levels of engagement in risky driving remained fairly stable across the sample over early adulthood.

5. Risky driving and substance use

Early adulthood can be a period of considerable risk-taking. The prevalence of substance use reaches a life-time high (Spooner, Hall & Lynskey, 2001), while other forms of risk-taking common at this age include antisocial behaviour, gambling and risky driving. The co-occurrence of risk-taking behaviours can be extremely harmful - even fatal. This chapter focuses particularly on the co-occurrence of risky driving and substance use.

When combined with driving, substance use may have lethal consequences. Substance use can affect the way a driver thinks and feels, the speed with which they react, and their hand-eye coordination. Consequently, drug-taking has the potential to impair a person's ability to drive safely (Drummer, 2008; Shinar, 2006).

The detrimental effects of alcohol on driving ability have been widely documented. Research suggests that alcohol increases a driver's risk of crashing six-fold (Task Force On Drug Abuse, 1996). Furthermore, alcohol is the most commonly detected substance among drivers killed or injured in motor vehicle crashes (Drummer, 2008; Longo, Hunter, Lokan, White, & White, 2000; Mercer & Jeffery, 1995), with alcohol implicated in 25-30% of road fatalities in Australia (Drummer, 2008).

Less is known about the impact of other drugs on driving performance. However, there is increasing evidence that drugs such as marijuana, amphetamines, ecstasy and benzodiazepines impair driving ability (Drummer, 2008; Mallick, Johnston, Goren, & Kennedy, 2007). Further, a combination of drugs, such as alcohol and marijuana or alcohol and benzodiazepines, can have a greater impact on driving ability than when used on their own (Mallick et al., 2007).

Rates of driving when under the influence of alcohol or illegal substances are particularly high among young drivers. A recent Australian study of drivers aged between 16 and 84 years found that 20-29 year olds were the most likely to have driven when under the influence of alcohol in the previous year, while this age group was the second most likely (after 16-19 year olds) to report having driven within three hours of using ecstasy or methamphetamines (Mallick et al., 2007). Additionally, Drummer and colleagues (2003) found that 22-30 year olds were over-represented among alcohol- and drug-affected drivers killed in three Australian states between 1990 and 1999.

There is also evidence that young people who drive when affected by drugs more often engage in unsafe driving practices such as speeding, failing to wear a seatbelt and taking risks in traffic (Donovan, 1993; Fergusson & Horwood, 2001; Steptoe et al., 2002, 2004). Similarly, in previous ATP research, alcohol use, binge drinking, cigarette use and marijuana use were found to be more common among high-level risky drivers aged 19-20 years than among low- or moderate-level risky drivers (Vassallo et al., 2008). Smart & Vassallo (2005) also showed that there is considerable overlap in the risk factors for risky driving, antisocial behaviour and substance use, suggesting that these differing forms of risk-taking shared common childhood and adolescent precursors. Precursors common to all three types of risk-taking included a less persistent temperament style, aggressive and hyperactive behaviour problems, school adjustment difficulties, friendships with antisocial peers and poorer parent-child relationships.

There are many issues that could be explored regarding the co-occurrence of risky driving and substance use. This chapter addresses two main questions. The first focuses particularly on drink-driving and whether young drink-drivers are also prone to engage in other types of risky driving. The second looks at whether young people who are high-level risky drivers also engage in higher levels of substance use, both singly and in combination. The two questions addressed are:

• Do young people who drink and drive engage in other unsafe driving behaviours more often than other young drivers who do not drink and drive?
• Do young people who frequently engage in risky driving use substances more often than other young drivers?

5.1 Co-occurrence of drink-driving and other types of risky driving

Young people who drink and drive were identified on the basis of their responses to two questions: (a) whether they had driven when near or over the alcohol limit during the past month, and (b) on how many of their past ten trips they had driven when affected by alcohol. This combination of questions was used to ensure that all instances of drink-driving were captured. For example, young people who drive very frequently might have undertaken their last 10 trips in a very short period of time (e.g., the past week), and for them it is important to include a question covering a wider time frame. On the other hand, those who drive infrequently might not be captured in the question about drink-driving in the past month, and the question about their last 10 trips might provide a broader sample of their driving behaviour.

Young people who responded affirmatively to either question were classified as drink-drivers ( n = 277, 28% drivers), while the remainder were classified as other drivers ( n = 703, 72% drivers).

The two groups were then compared on (a) whether or not they had engaged in other risky driving behaviours (speeding, seatbelt or helmet use, driving when fatigued, driving when affected by illegal drugs and mobile phone use when driving); and (b) how often they engaged in other types of risky driving.⁵⁰

Engagement of young drink-drivers in other types of risky driving

We look first at whether or not young drink-drivers engaged in other types of risky driving by comparison with other young drivers.

Drink-driving was strongly associated with speeding, as shown in Figure 22. Significantly more drink-drivers had exceeded the speed limit (by all margins) than those who did not drink-drive.⁵¹ These group differences were particularly evident for the highest speeding category: close to 30% of drink-drivers had exceeded the speed limit by over 25 km/h on a recent trip, compared with only 8% of other drivers.

Figure 22. Percentage who exceeded the speed limit at least once during their past 10 trips, drink-drivers and other drivers, at 23-24 years

Odds ratios can be used to estimate the likelihood of an outcome occurring (e.g., a crash) if a certain factor is present (e.g., speeding). Odds ratios can range from 0 to infinity. Values close to 1.0 indicate no relationship between the factor and an outcome. Values greater than 1.0 suggest that as levels of the factor increase (e.g., speeding), so does the likelihood of an outcome (e.g., a crash), while values smaller than 1.0 suggest that an outcome (e.g., a crash) is less likely as levels of the factor increase (e.g., completion of a defensive driving course).

Odds ratios comparing drink-drivers and other drivers indicated that drink-drivers were more than four times more likely to engage in low-level speeding (up to 10 km/h over limit), 3.4 times more likely to report moderate-level speeding (11-25 km/h over limit) and five times more likely to engage in high-level speeding (more than 25 km/h over limit).⁵²

Young drink-drivers were significantly more likely to have not worn a seatbelt or helmet for all or part of a recent driving trip (Figure 23).⁵³ More than a quarter had driven without a seatbelt/helmet for part of a recent trip, compared with 8% of other drivers (odds ratio of 4.2), while one in ten drink-drivers had driven without a seatbelt/helmet for all of a trip, compared with only 3% of other drivers (odds ratio of 3.0).

Figure 23. Percentage who had not worn a seatbelt for part or all of at least one recent trip, drink-drivers and other drivers, at 23-24 years

Driving when fatigued was significantly related to drink-driving, with a higher proportion of drink-drivers reporting that they had recently driven when very tired, and had nearly fallen asleep or fallen asleep when driving (Figure 24).⁵⁴ Three-quarters of drink-drivers reported that they had driven when very tired on at least one of their past ten trips, compared with 58% of other drivers (odds ratio of 2.1), and one in six had fallen asleep or come close to falling asleep on a recent trip, compared to 9% of other drivers (odds ratio of 2.1).

Figure 24. Percentage who had driven when fatigued at least once during their past 10 trips, drink-drivers and other drivers, at 23-24 years

Young drink-drivers were also significantly more likely to have driven when affected by illegal drugs. As Figure 25 shows, while rates of driving when under the influence of illegal drugs were generally very low, drink-drivers were considerably more likely than other drivers to have driven when affected by marijuana (odds ratio of 5.8), ecstasy (odds ratio of 9.7) and/or amphetamines (odds ratio of 4.5).⁵⁵

Figure 25. Percentage who had driven when affected by an illegal drug at least once during their past 10 trips, drink-drivers and other drivers, at 23-24 years

Finally, young drink-drivers were significantly more likely than other young drivers to have used a handheld mobile phone when driving (Figure 26). Three-quarters had talked on a handheld mobile on at least one of their ten most recent trips, compared with 46% of other drivers (odds ratio of 3.7), while over 80% had used a mobile phone function (e.g., received or sent an SMS) when driving, compared to 59% of other drivers (odds ratio of 3.0).⁵⁶ However, the two groups did not significantly differ in their use of hands-free mobile phones when driving.

Figure 26. Percentage who had used a mobile phone when driving at least once during their past 10 trips, drink-drivers and other drivers, at 23-24 years

Engagement of young drink-drivers in other types of risky driving

A second way of looking at the co-occurrence of drink-driving and other types of risky driving is to explore whether young drink-drivers engage in other risky driving practices more frequently. Table 18 shows that young drink-drivers had engaged in almost all other types of risky driving more often than other young drivers.

For example, drink-drivers had engaged in low-level speeding on about half of their ten most recent trips, while other drivers had done so on only about a third of trips. Similarly, while drink-drivers had exceeded the speed limit, used a handheld mobile when driving, or driven when very tired on about 20% of trips, other drivers had engaged in these unsafe driving practices on fewer occasions (between 10% and 15% recent trips). Rates of other forms of risky driving were less frequent (occurring on fewer than 10% of trips), but occurred more often among drink-drivers. There were also trends for differences on failure to wear a seatbelt or helmet for the duration of a trip and driving when affected by amphetamines.

5.2 Comparison of substance use among high-level risky drivers and other drivers

The second question investigated was whether young people who frequently drove in a risky manner more often used legal and illegal substances than other young drivers, both singly and in combination.

To investigate this question, the groups identified at 23-24 years who showed low (n = 630), moderate (n = 261) and high (n = 57) levels of risky driving (as described in Chapter 4, Table 15) were compared. These groups are hereafter referred to as low-, moderate- and high-level risky drivers.

For these analyses, responses to questions about the number of days on which various substances had been used in the past month were examined. The substance use types considered were: alcohol, binge drinking, marijuana, ecstasy and amphetamines. High-level binge drinking was defined as having 5 or more drinks in quick succession for males and 3 for females, while very high-level binge drinking was defined as having 7 or more drinks for males and 5 or more for females.

The use of other types of illegal substances such as heroin, cocaine and hallucinogens was not investigated, as the numbers of young people who reported using these substances was too small for reliable statistical analyses to be undertaken.

Alcohol use and binge drinking

The low-, moderate- and high-level risky driving groups did not differ on the number of days in which they had consumed alcohol during the past month.⁵⁷

However, while the majority of young people in each risky driving group had engaged in binge drinking at least once during the past month, the low-level risky driving group was least likely to have consumed alcohol at high and very high levels (Figure 27).⁵⁸

Odds ratios indicated that the moderate-level risky driving group was almost twice as likely as the low-level group to have engaged in high- and very high-level binge drinking.⁵⁹ While rates of high- and very high-level binge drinking were similar among the high- and moderate-level risky driving groups (Figure 27), the odds ratios comparing the high- and low-level risky driving groups were not significant. It is probable that the size of the high-level risky driving group (n = 57) was too small to detect statistically significant group differences.

Figure 27. Engagement in high- and very high-level binge drinking in the past month, low-, moderate- and high-level risky drivers, at 23-24 years

Marijuana, ecstasy and amphetamine use

Significant connections were found between risky driving and marijuana use.⁶⁰ Considerably more high-level risky drivers (30%) had used marijuana in the past month than moderate- (15%) and low-level risky drivers (10%). Odds ratios indicated that the high-level group was almost 4 times more likely than the low-level group to have used marijuana in the past month.⁶¹ Young people in the low- and moderate-level groups did not significantly differ in their likelihood of using marijuana.

The risky driving groups also significantly differed in their use of ecstasy. Fourteen per cent of the high-level group, and 12% of the moderate-level group had used ecstasy in the past month, compared with 7% of the low-level group. Odds ratios showed that moderate-level risky drivers were more than twice as likely as low-level risky drivers to have used ecstasy. As found earlier in relation to binge drinking, while ecstasy use was a little more common among the high-level group than the moderate-level group, the high-level group did not significantly differ from the low-level group in their likelihood of ecstasy use. Once again, the small size of the high group may have been responsible for this finding.

Finally, amphetamine use was significantly related to risky driving, with those in the low-level group the least likely to have used this type of drug in the past month.⁶² Fourteen per cent of the high-level group and 10% of the moderate-level group had recently used amphetamines, compared with 6% of the low-level group. As levels of risky driving increased so did amphetamine use, with moderate-level risky drivers almost twice as likely as low-level risky drivers to have recently used amphetamines, and high-level risky drivers 2.8 times more likely to have used amphetamines within the past month.

Multi-substance use

To investigate connections between risky driving and multi-substance use, the three risky driving groups were compared on (a) the number and frequency of use of differing substances in the past month, and (b) rates of combined marijuana use and binge drinking.

Number and frequency of differing substances used

As noted earlier, young people provided information about the number of days during the past month they had used various substances (alcohol, marijuana, ecstasy, amphetamines, methamphetamines, heroin, cocaine, inhalants, hallucinogens, or other illegal drugs). A total multi-substance use score was calculated for each individual by summing the number of different substances he or she reported using during the past month. The maximum possible score on this index was 10.

Figure 28 shows that two-thirds of ATP study members had used one type of substance in the past month, about 10% had used two different substances, and a similar proportion had used three or more substances. The highest number of different substances reported was 7, while 12% had not used alcohol or other drugs in the past month.

Figure 28. Number of substances used in the past month, ATP sample, at 23-24 years

Comparisons of the three risky driving groups revealed that individuals in the high- and moderate-level groups had used significantly more substances than those in the low-level group.⁶³ On average, the high-level group had used 1.6 different types of substances in the past month (SD = 1.3), whereas those in the moderate-level group had used 1.4 types (SD = 1.1) and those in the low-level group had used 1.2 different substances (SD = 0.9).

We next sought to determine whether high-level risky drivers used multiple substances more often than other drivers. Two steps were used to identify frequent multi-substance users as follows:

• those in the highest 20% of the ATP sample on binge drinking, marijuana, ecstasy or amphetamine use were classified as frequent users of the particular drug type, and the remainder of the sample was classified as not frequent users of the drug; and
• a total frequent multi-substance use score was calculated for each individual by summing the number of different substances on which he or she had been classified as a frequent user. The maximum possible score was 4.

Figure 29 shows the ATP sample's distribution of scores on the frequent multi-substance use index. Approximately two-thirds did not frequently use any substance. Just over one in five were frequent users of one substance, and about 7% were frequent users of two different substance types. Very few (about 3%) were frequent users of more than two substances.

Figure 29. Frequent multi-substance use in the past month, ATP sample, at 23-24 years

Comparison of the three risky driving groups revealed that the high-level group was significantly more likely than the low-level group to have frequently used several substances (Figure 30).⁶⁴ Odds ratios indicated that high-level risky drivers were almost five times more likely than low-level risky drivers to have frequently used two or more different substances within the past month, and were also 2.4 times more likely to have been a frequent user of one substance.⁶⁵ In addition, moderate-level risky drivers were more than twice as likely as low-level risky drivers to have frequently used two or more substances, and one-and-a-half times more likely to have frequently used one substance.⁶⁶

Figure 30. Frequent multi-substance use in the past month, high-, moderate- and low-level risky drivers, at 23-24 years

Risky driving and combined binge drinking and marijuana use

Four groups with differing patterns of frequent binge drinking and marijuana use were formed, using the criteria described in the previous sub-section to identify frequent multi-substance use. The four groups were: a neither group, a binge drinking only group, a marijuana use only group, and a both group. The proportions in each group are shown in Table 19.

High- and moderate-level risky drivers significantly differed from low-level risky drivers in their combined use of alcohol and marijuana (Figure 31).⁶⁷ Only one-quarter of the low-level group were frequent binge drinkers, marijuana users or both, by comparison with half the high-level group and over a third of the moderate-level group.

Differences were particularly marked for combined alcohol and marijuana use, with 18% of the high-level group found to be frequent users of both substances, compared with only 5% of the low-level group and 6% of the moderate-level group. Odds ratios indicated that high-level risky drivers were almost 6 times more likely than low-level risky drivers to both binge drink and use marijuana frequently, and 3.3 times more likely to frequently use marijuana alone.⁶⁸ Moderate-level risky drivers were about twice as likely to frequently use marijuana, and about one and a half times more likely to frequently binge drink than low-level risky drivers.⁶⁹

Figure 31. Frequent binge drinking and marijuana use in the past month, high-, moderate- and low-level risky drivers, at 23-24 years

5.3 Discussion and implications

This chapter examined connections between risky driving and substance use in two ways. Firstly, it looked at whether young drink-drivers were more likely to engage in other forms of risky driving than other young drivers. Speeding, driving without a seatbelt, when fatigued, under the influence of an illegal drug or when using a mobile phone were all more common among young drink-drivers than other young drivers. Differences were particularly evident on speeding, driving while under the influence of illegal drugs, or driving without a seatbelt.

Secondly, low-, moderate- and high-level risky drivers were compared to determine whether high- and moderate-level risky drivers were more likely to use substances than low-level risky drivers, both singly and in combination. Binge drinking and marijuana, ecstasy and amphetamine use were significantly higher among the high- and moderate-level groups than the low-level group, with the strongest differences found on binge drinking and marijuana use. Further, high- and moderate-level risky drivers were more likely to use multiple substances, and did so more frequently.

Some implications that can be drawn from these findings and earlier findings from this report are discussed next.

Most young people planned ahead to avoid drink-driving

As noted earlier (Table 8), 23% of 23-24 year olds had driven when under the influence of alcohol on at least one occasion in their past ten trips. As alcohol has been shown to increase a driver's risk of crashing six-fold (Task Force on Drug Abuse, 1996) and is implicated in 25-30% of road fatalities in Australia (Drummer, 2008), this rate is concerning. Clearly, road safety efforts targeting drink-driving among young people continue to be necessary.

Current initiatives encourage young people to plan ahead to avoid drink-driving and Section 3.1 showed that young people used a variety of strategies to achieve this, such as forward planning, reducing consumption, finding another way home or staying overnight. These differed across males and females, those living in metropolitan and non-metropolitan areas, and those with differing levels of educational attainment. In all, two-thirds of the ATP cohort always planned ahead, while a further 17% made plans most of the time. However, almost one in ten (9%) rarely or never made plans to avoid drink-driving. Further efforts may be needed to reach this group. Of the 91% who made plans to avoid drink-driving, three-quarters subsequently never engaged in drink-driving. However, about one in five of this group went on to drink and drive on rare occasions, while 1% did so most of the time or always.

These findings suggest that current initiatives are hitting their mark, since the majority of young people successfully devised and used strategies to avoid drink-driving. Nevertheless, a small number did not make plans, and of those who made plans, almost a quarter ended up drink-driving at least occasionally. Further work is needed to understand why some young people do not plan ahead or are unable to carry out their plans. For example, is this a result of their personal style (such as impulsiveness, low self-control), peer group influences, lack of availability of alternative forms of transport, other circumstances, or a mix of these factors? The intervention implications arising from these alternative explanations would differ considerably. Identification of the types of drink-driving avoidance strategies that have the highest rates of success could also provide valuable information to inform road safety efforts and would enable better targeting of sub-groups who use differing strategies (e.g., metropolitan and non-metropolitan youth, males and females).

Drink-driving co-occurred with other forms of risky driving

The findings provide insight into the broader driving behaviour of young people who drink and drive. They suggest that drink-driving is not an isolated phenomenon and tends to occur in tandem with other forms of risky driving. Thus, odds ratios showed that young drink-drivers were 5 times more likely than other young drivers to have driven in excess of 25 km/h above the limit, not worn a seatbelt during a trip, or to have used a mobile phone when driving; between 4 and 9 times more likely to have driven when under the influence of an illegal drug (depending on the type of substance used); and twice as likely to have driven when very tired. Hence, there was considerable overlap between drink-driving and other types of risky driving.

These findings are in keeping with other research showing inter-connections between differing types of risky driving practices. Laapotti and Keskinen (2008), when comparing the fatal crashes of young and middle-aged Finnish male drivers, concluded that drink-driving is an aspect of a more pervasive risky driving style for young male drink-drivers. Donovan (1993) showed that drink-driving co-occurred with driving under the influence of illegal substances and other forms of risky driving (e.g., speeding, unsafe passing, lane changing), with inter-correlations between the three problem driving outcomes of between .24 and .46. Other research has shown that young people who drink and drive are more likely to drive above the speed limit and be apprehended for driving-related offences (Engström et al., 2003; Palamara & Stevenson, 2003; Steptoe et al., 2004).

Taken together, the findings of the present study and other research suggest that drink-driving is not an inadvertent or aberrant occurrence, but is often part of a more general risk-taking approach to driving. Hence, road safety efforts that emphasise conscious decision-making and pre-planning, while successful for less risky drivers, may not be as effective with individuals who engage in high-level risky driving practices.

The attractions of drink-driving need to be considered and tackled. Fry and Holden (2007), in a qualitative study of 53 Australian 17-25 year olds, found that the sub-group who regularly drove after binge drinking saw this as part of their personal "mobility" and "independence", found drink-driving exciting, and had fatalistic attitudes towards the possibility of a crash or apprehension by police. They also tended to believe that they remained skilled drivers when drunk, with heightened perceptions. In contrast, their more law-abiding counterparts focused on moral and societal obligations, feelings of responsibility towards others, and the potential negative impacts they might experience as a result of drink-driving (e.g., on their mobility, employment and career prospects, interpersonal relationships).

These findings reveal two quite different mindsets, suggesting that these groups may need to be targeted differently. For instance, these findings suggest that drink-drivers are more individualistic, and self-focused in their attitudes than other drivers; hence it is possible that road safety efforts that focus on the negative consequences of drink-driving on others will not resonate as strongly with this group as with other drivers. Rather, initiatives that focus on adverse consequences of drink-driving for the drivers themselves might have greater impact. Hence, interventions focusing on the negative personal impacts of drink-driving (e.g., loss of friends, reputation, etc.) might be one means of reaching this group. However, further research is needed to confirm the efficacy of such an approach. Additionally, this group's misconceptions of having enhanced driving skills and heightened perceptions when driving under the influence of alcohol are clear-cut targets for road safety efforts.

A second implication of these findings is that road safety campaigns aimed at decreasing risky driving practices in general are likely to have a flow-on effect on drink-driving. As Shope and colleagues have suggested (Shope, Waller, & Lang, 1996; Shope, Waller, Raghunathan, & Patil, 2001) interventions to prevent risky driving will also reduce drink-driving and driving under the influence of illegal drugs, since these risky driving practices are substantially inter-linked. Thus, specifically targeted strategies (e.g., Victoria's booze bus drink-driving program) and more general road safety initiatives (e.g., population-targeted publicity campaigns) can both play a role in decreasing drink-driving among young people.

High-level risky drivers used alcohol and other drugs more often

A further issue addressed in this chapter was whether high-level risky drivers engaged in alcohol and other drug use more often than low-level risky drivers. This was clearly the case; for example, high-level risky drivers were almost 4 times more likely to have used marijuana in the past month and were almost 3 times as likely to have used amphetamines. Additionally, they were more likely to be multi-substance users, and to use multiple substances more frequently.

These findings are consistent with other research (e.g., Caspi et al., 1997). For instance, Beirness and Simpson (1988) found that risky driving - as measured by behaviours such as deliberate risk-taking when driving, failure to wear seatbelts, and driving while under the influence of alcohol or drugs - was associated with alcohol and other drug use in a sample of Canadian high school students. Similarly, Shope and Bingham (2002) found that young US adults who drove when affected by alcohol were more likely than other young people to report problem drinking, drug use and delinquency.

These findings also extend earlier ATP research (Vassallo et al., 2008) showing that risky driving co-occurred with several externalising problems at 19-20 years (alcohol, cigarette and marijuana use; binge drinking; antisocial behaviour), with co-occurrence being most noticeable for antisocial behaviour and marijuana use at this age. Similar links between substance use and risky driving were evident here at 23-24 years of age. As at 19-20 years, marijuana use was particularly associated with risky driving at 23-24 years. Additionally, just over half of the high-level group had frequently used alcohol, marijuana or both, a rate that was almost double that of the low-level group.

One conclusion that could be drawn from these findings is that risky driving is one element of a risk-taking lifestyle for a number of young people. As such, young risky drivers are likely to benefit from interventions that not only target their behaviour on the road, but also other aspects of their lives, such as their use of legal and illegal substances. Thus, while specific programs targeting risky driving will remain essential, more broad-based "common solutions" approaches may also play a role in decreasing risky driving.

Interestingly, 23-24 year old moderate-level risky drivers also significantly more often engaged in binge drinking, ecstasy and amphetamine use than low-level risky drivers, and were twice as likely to be frequent multi-substance users. This finding demonstrates a co-occurrence between risky driving and substance use even at moderate levels of risky driving. It is possible that the moderate-level group was also attracted to risk-taking, albeit at lower levels than the high-level group. If so, similar broad-based interventions might have success in reducing this group's engagement in problem behaviours, including risky driving. As the numbers who engage in moderate-level risky driving tend to be much larger than the number who are high-level risky drivers (261 vs 54 in this particular study), the benefits to road safety could be quite large.

Risky driving may reflect an underlying propensity for problem behaviours

The co-occurrence of risky driving and substance use found here could be seen as supportive of Problem Behaviour Theory (Jessor, 1987; Jessor et al., 1997), which proposes that problem behaviours are interrelated and reflect a basic underlying trait or propensity. This theory implies that both targeted and more generalist intervention and prevention approaches will be effective in decreasing a range of problem behaviours, including risky driving. For example, programs addressing risky driving among young traffic offenders, broader initiatives that target multiple problems (e.g., drink-driving, driving under the influence of other drugs), and population-wide initiatives that aim to increase community awareness (e.g., media campaigns addressing speeding) could be expected to affect risky driving and other problems behaviours as well.

However, the overlap between risky driving and substance use was partial, not complete. For example, only approximately a third of 23-24 year old high-level risky drivers had used marijuana within the past 30 days and just over two-thirds had not. These findings support Willoughby, Chalmers, & Busseri's (2004) conclusion that while problem behaviours share common elements, they remain distinct phenomena. The findings also demonstrated that the high-level risky driving group was heterogeneous, containing young people showing differing profiles of problem outcomes that range from involvement in a single problem to involvement in several types of problem behaviours. Given this heterogeneity, no single approach is likely to be solely effective in reducing risky driving. Rather, a range of intervention and prevention efforts would appear to be needed to reduce risky driving among young people.

Conclusions

This chapter looked at connections between risky driving and substance use. Firstly, young people who drove when under the influence of alcohol more often engaged in other types of risky driving (e.g., speeding, not wearing a seatbelt) than their peers who did not drink and drive. Secondly, high- and moderate-level risky drivers more often used legal and illegal substances than low-level risky drivers. Thus, risky driving and substance use frequently co-occurred, and may be one element of a risk-taking lifestyle for a number of young people.

6. Crash involvement, speeding and fatigued driving

This chapter follows on from the previous chapter, which looked at links between drink-driving and other types of risky driving, to examine inter-connections between three other problematic driving outcomes - crash involvement, high-level speeding, and fatigued driving.

It is well established that young drivers are particularly prone to involvement in crashes. For example, rates of crash-related injuries or deaths are considerably higher among young drivers than older drivers (Cavallo & Triggs, 1996; Dunsire & Baldwin, 1999; Palamara & Stevenson, 2003; Transport Accident Commission, 2009). Recent road safety statistics show that while 18 to 25 year olds represented only 14% of licenced drivers in Victoria in 2007, they accounted for 28% of drivers killed in road traffic accidents during that year (TAC, 2009b). Additionally, transport accidents were the leading cause of death among Australians aged 15 to 25 years in 2004 to 2006 (Australian Bureau of Statistics, 2008).

Two risky driving practices place young drivers at particularly high risk of serious crashes - speeding and driving when fatigued (Dobbie, 2002; Palamara & Stevenson, 2003). Both practices influence an individual's ability to drive safely, by affecting their ability to react to unexpected road events and take evasive action if required. For instance, a driver who speeds has less time to respond to changes in their environment, experiences a reduction in car manoeuvrability, and requires a longer stopping distance than a driver who observes the speed limit (Aarts & Van Schagen, 2006; Liu, Chen, Subramanian, & Utter, 2005; Williams, Kyrychenko, & Retting, 2006). A fatigued driver may be less attentive, experience impairments in judgement, and take longer to react to dangers in their driving environment than a more alert driver, or in some cases, may fall asleep and crash (Dobbie, 2002; Stutts, Wilkins, Osberg, & Vaughn, 2003). For these reasons, speed- and fatigue-related crashes tend to be among the most severe types of crashes, more often resulting in injury or death (Aarts & Van Schagen, 2006; Dobbie, 2002).

Both risky driving practices appear to be quite common among young drivers. For instance, looking at the prevalence of these behaviours among young adults participating in the Australian Temperament Project, most had engaged in low-level speeding (i.e., up to 10 km/h over the limit) on at least one of their ten most recent driving trips (84% at 19-20, 83% at 23-24 years) and about half were involved in moderate-level speeding (i.e., 11-25 km/h over the limit: 49% at 19-20, 45% at 23-24 years). Fatigued driving was also very common, with about two-thirds of young people having recently driven when very tired (64% at 19-20 and 63% at 23-24) (see Smart & Vassallo, 2005, and Chapter 3 of this report for further details).While there has been considerable interest in whether risky driving co-occurs with other problematic behaviours such as substance use and antisocial behaviour (Beirness & Simpson, 1988; Shope & Bingham, 2002; Smart & Vassallo, 2005; Vassallo et al., 2008), less is known about the degree to which different road safety behaviours themselves are inter-related. Such information could assist those working in the road safety field to appropriately target their intervention efforts. For instance, knowing whether the same group of young people who engage in one form of risky driving (e.g., speeding) are also more likely to engage in other risky driving practices (e.g., driving when fatigued) may be useful in determining whether generalist or more targeted intervention approaches are needed to combat particular unsafe driving practices.

Several studies have shown that drivers who disregard speed limits are more likely to drink and drive, to have a history of speeding and driving-related offences and to speed at night (Harrison, Fitzgerald, Pronk, & Fildes, 1998; Palamara & Stevenson, 2003; Steptoe et al., 2004). Fatigued drivers are more likely to spend longer periods behind the wheel, and to more often drive late at night or during the early hours of the morning than other drivers (Connor et al., 2002; Stutts et al., 2003). Furthermore, those involved in fatigue-related crashes are more likely to have engaged in other risky driving practices such as drink-driving and excessive speeding (Dobbie, 2002; Engström et al., 2003; Pack et al., 1995). However, many of these studies have been conducted overseas and have focused on drivers of varying ages rather than young adults. Australian research examining the co-occurrence of different unsafe driving behaviours among young drivers remains limited.

This chapter will examine the degree of overlap between three different problematic driving outcomes at 23-24 years. Two steps will be taken to address this issue. First, we examine whether young people who have been involved in multiple crashes, engaged in high-level speeding, or driven when tired, differ from other young drivers on their driving history, on-the-road experiences, and involvement in other forms of risky driving. Second, we will compare the multiple crash, high-level speeding and fatigued driving groups to explore their similarity on these characteristics, as well as the degree to which the same individuals are involved in these three types of problem driving outcomes.

The following aspects will be investigated:

• driving history (as assessed by the length of time licences have been held);
• number of hours currently spent driving each week, and the times at which driving occurs;
• rates of apprehension for driving-related offences; and
• engagement in other risky driving behaviours.

6.1 Crash involvement

Young people were divided into three groups on the basis of the number of crashes they had been involved in as drivers since starting to drive.⁷⁰ These were:

• a zero crash group (n = 392, 42% of drivers);
• a single crash group (n = 284, 30%); and
• a multiple crash group (2 to 6 crashes; n = 259, 28%).

The groups did not significantly differ on gender composition, with a similar ratio of males to females in each group.

The zero, single and multiple crash groups were compared on the length of time they had held their licences; the amount of time they spent driving each week and the times at which this typically occurred; their rate of committing driving-related offences; and their engagement in a range of risky driving behaviours. The results of these comparisons follow.⁷¹

While most of the ATP cohort had held a licence for close to 6 years, individuals in the multiple crash group tended to have held their licences longer than those in the zero crash group.⁷² Thus, the multiple crash group had held their licences for an average of 6 years and 2 months, compared to an average of 5 years and 10 months for the single crash group, and 5 years and 9 months for the zero crash group.

Young people in the three crash groups did not significantly differ in the total amount of time they spent driving each week, or in the amount of time that they spent driving at particular times of the day or week.

On average, young people in the multiple crash group had been detected speeding on significantly more occasions (M = 2.3, SD = 2.5) than those in the single (M = 1.3, SD = 1.6) and zero crash groups (M = 1.1, SD = 2.5).⁷³ Multiple crash group members were also significantly more likely than individuals in the other two groups to have had police contact for a driving-related offence in the past year (22% vs 13% of the single and 9% of the zero crash groups).⁷⁴ Furthermore, young adults in the multiple crash group had significantly more often had their licence suspended or cancelled than those in the single or zero crash groups (14% of the multiple crash group, compared to 4% of the single and zero crash groups).⁷⁵

The multiple crash group had experienced more crashes resulting in property damage than the single crash group, but not more crashes resulting in injury or death.⁷⁶

As can be seen from Table 20, the multiple crash group was significantly more likely than the other two groups (but particularly the zero crash group) to have engaged in most forms of risky driving. Thus, a higher percentage of the multiple crash group had exceeded the speed limit, driven when fatigued, driven when affected by illegal drugs, or used a mobile phone when driving on at least one of their ten most recent driving trips. There were also trends for differences on driving when affected by alcohol and having nearly fallen asleep or fallen asleep when driving.

Differences were particularly evident for speeding and mobile phone use when driving. For instance, more than half of the multiple crash group (55%) had recently exceeded the speed limit by 11-25 km/h, compared with 43% of the single crash group and 38% of the zero crash group. Similarly, while talking on a handheld mobile phone when driving was relatively common overall, the proportion of young people in the multiple crash group who had engaged in this behaviour (66%) was noticeably higher than among the single and zero crash groups (about 50% in each group).

6.2 Speeding

Young people who had exceeded the speed limit by more than 25 km/h on at least one of their ten most recent trips (high-level speeders; n = 131, 14% of drivers) were compared to those who had not (other drivers; n = 828, 86%). The majority of high-level speeders were male (70%), while females were more likely than males to be classified as other drivers (66% of this group was female).⁷⁷

The two speeding groups did not differ on the average length of time they had held their driver's licences.

Young people who engaged in high-level speeding spent significantly more hours behind the wheel than other drivers (on average, 13 hours per week, compared to 10 hours for other drivers).⁷⁸ Looking more closely at when driving occurred, high-level speeders spent significantly more hours driving at night on weekdays than other drivers (2.8 hours vs 2 hours) and there were trends for differences on rates of weekend driving.⁷⁹

As might be expected, high-level speeders had been detected speeding significantly more often than other drivers,⁸⁰ having been detected on average 3 times during their driving careers (M = 3.2, SD = 4.2), compared with an average of just over one instance of being detected among other young drivers (M = 1.3, SD = 1.7). Similarly, high-level speeders were significantly more likely to have had contact with police regarding a driving-related offence in the past 12 months (31% vs 11%).⁸¹ High-level speeders had also significantly more often had their licence cancelled or suspended at some time during their driving careers (19% vs 5%).

While similar proportions of high-level speeders and other drivers had been involved in a crash at some stage during their driving career, focusing only on those who had been involved in a crash, high-level speeders were found to have been involved in more crashes than other drivers (1.4 crashes compared to 0.9 crashes).⁸² Looking at the circumstances of these crashes, high-level speeders had been involved in more property damage crashes when driving alone than other drivers (high-level speeders: M = 1.7, SD = 1.1; other drivers: M = 1.3, SD = 0.8),⁸³ but did not differ in their rates of involvement in other crash types (property damage crashes when carrying passengers, injury crashes when driving alone or carrying passengers).

High-level speeders were compared to other young drivers on their engagement in risky driving. As can be seen from Table 21, high-level speeders were significantly more likely to have engaged in almost all other types of risky driving except talking on a hands-free mobile phone. Hence, a higher percentage of high-level speeders had exceeded the speed limit by low and moderate levels; not worn a seatbelt or helmet for all or part of a recent driving trip; had fallen asleep or nearly fallen asleep when driving; driven when affected by alcohol or marijuana; and/or talked on a handheld mobile phone or used a mobile phone function when driving. A similar trend was found for driving when very tired, but did not reach the adjusted significance level.

Note: ^a Groups were not compared on speeding by more than 25 km/h, as this was the criterion used to identify high-level speeders and other drivers. ^b Groups were not compared on driving when affected by ecstasy or amphetamines, as the number of individuals in the high-level speeding group who had engaged in these behaviours was too small for reliable statistical comparisons.

Rates of these behaviours differed markedly across the two groups. For instance, not surprisingly, virtually all of the high-level speeding group (99%) had engaged in moderate-level speeding (between 11 and 25 km/h) during at least one of their ten past trips compared with just over a third of other drivers (36%). The percentage of high-level speeders who had engaged in highly dangerous behaviours such as driving when affected by alcohol (53%) or falling asleep or nearly falling asleep when driving (27%) was also much higher than among other drivers (18% and 8% respectively).

6.3 Fatigued driving

To determine whether fatigued drivers significantly differed from other drivers, ATP study members were divided into two groups on the basis of how often they had driven when very tired during their past ten trips. Two groups were identified:

• those who had driven when very tired on two or more of their ten most recent driving trips (fatigued drivers; n = 364, 38% of drivers); and
• those who had not (other drivers; n = 599, 62%).

While the groups differed on gender composition, with more females than males being in the fatigued drivers group (66%), these differences did not reach the adjusted significance level.⁸⁴

The two groups did not significantly differ on the average length of time they had held their driver's licences.

As shown in Figure 32, fatigued drivers spent significantly more hours driving in total per week, and driving at different times of the weekend, with trends for driving more often during the week as well.⁸⁵

Figure 32. Number of hours spent driving, at weekdays and weekends and during daylight and night-time hours, fatigued drivers and other drivers, at 23-24 years

Fatigued drivers had not been detected speeding more often than other drivers,⁸⁶ but were significantly more likely to have had police contact for a driving-related offence in the past year (18% vs 12%).⁸⁷ However, they did not significantly differ on rates of licence cancellation or suspension.

Fatigued drivers were significantly more likely than other drivers to have been involved in a crash while driving (67% versus 56%),⁸⁸ and had also been involved in more crashes on average (fatigued drivers: M = 1.2 crashes, SD = 1.1; other drivers: M = 0.9 crashes, SD = 1.1).⁸⁹ Looking at the characteristics of these crashes, young people who had driven when very tired had been involved in more crashes resulting in property damage when they had passengers in the car (fatigued drivers: M = 0.9, SD = 0.7; other drivers: M = 0.7, SD = 0.6).⁹⁰ There were no significant differences on the circumstances and outcomes of other crash types (property damage when driving alone; injury or death when driving alone or when with passengers).

In terms of involvement in other forms of risky driving, Table 22 shows that fatigued drivers had significantly more often engaged in most types of risky driving. Not surprisingly, the most powerful differences between fatigued drivers and other drivers were on the percentage who had fallen asleep or nearly fallen asleep while driving (25% versus 3%). Additionally, large differences were also found on speeding and mobile phone use when driving. For instance, more than half of fatigued drivers (57%) had engaged in moderate-level speeding, compared to 37% of other drivers, while two-thirds (66%) of fatigued drivers had talked on a handheld mobile when driving, compared to 48% of other drivers. There were also trends for differences on failure to wear a seatbelt for the duration of a trip and driving when affected by marijuana or amphetamines.

Note: ^a Groups were not compared on "Drove when very tired", as this was the criterion used to identify fatigued drivers and other drivers.

6.4 Similarities and differences between problematic driving outcome groups

A summary of the characteristics that were significantly related to each of the three problematic driving outcomes - crash involvement, high-level speeding and fatigued driving - is provided in Table 23. A cross (X) indicates that a particular road safety behaviour or characteristic (e.g., length of time licences have been held) was found to be associated with a specific outcome (e.g., crash involvement), while the absence of a tick indicates that a significant association was not found.

Note: ^a Group comparisons were not undertaken for these aspects due to low prevalence of these behaviours among one or more groups. ^b As the groups were defined on these variables, they were not compared on this aspect. T = trend.

There was considerable overlap in the factors associated with each outcome. Overall, 39% of the characteristics on which the groups were compared were common to all three problem driving outcomes. Overlap was especially evident on apprehension for driving offences and engagement in risky driving practices. Further, high-level speeding and fatigued driving shared 52% of characteristics in common, while crash involvement and high-level speeding, and crash involvement and fatigued driving, shared 50% of characteristics in common.

Some specific associations were also apparent. Length of time licences had been held was only associated with crash involvement. Type and amount of time spent driving was associated with high-level speeding and fatigued driving, but not with crash involvement. However, overall, there was a very high degree of overlap.

Next, the degree to which the same individuals were involved in multiple crashes, high-level speeding and fatigued driving was investigated. Table 24 shows that co-occurrence was very common, with 57% of drivers in the multiple crash group, 72% in the high-level speeding group, and 45% in the fatigued group also found to engage in another problem driving outcome. The highest degree of overlap was found between the multiple crash and fatigued driving groups, while for the high-level speeding group, the greatest level of overlap was with the fatigued driving group. Of concern is that one-fifth of high-level speeders had engaged in all types of problem driving outcomes, a rate much higher than among the multiple crash and fatigued driving groups, for whom rates were 11% and 8% respectively.

Note: A small number of individuals did not have complete data over all three outcomes and were excluded from this analysis.

These findings may reflect differences in group sizes to some extent, as the high-level speeding group was considerably smaller than the multiple crash and fatigued driving groups. They also suggest that high-level speeding may be a more extreme form of risky driving. High-level speeding (defined in this study as exceeding the speed limit by more than 25 km/h) is more likely to reflect an act of conscious risk-taking than fatigued driving or crash involvement.

6.5 Discussion and implications

This chapter examined the extent to which crash involvement, high-level speeding and fatigued driving were related to driver history, current on-the-road experiences, and other risky driving behaviours. This issue was addressed in two ways: first, by looking at the profile of each group separately and comparing these to other drivers; and second, by looking at the characteristics that were common or unique across the three problem driving outcomes, and the degree to which the same individuals were involved in the differing problem driving outcomes.

Looking first at each outcome, we found that young people who had been involved in multiple crashes tended to be slightly more experienced drivers, were more likely to have been apprehended for driving-related offences, and were more likely to have recently engaged in a wide range of risky driving practices than other drivers (particularly those who had never crashed).

Young drivers who engaged in high-level speeding and/or had driven when very tired on two or more recent trips also exhibited many of these characteristics. For instance, high-level speeders (who were predominantly male) had higher rates of apprehension for driving offences and were much more likely than other drivers to have engaged in a wide range of risky driving behaviours. In addition, this group spent more time on the road (particularly at night during the week) and had experienced higher rates of crashes than other drivers (especially property damage crashes when driving alone).

Similarly, fatigued drivers were more likely than others to have come to police attention for their behaviour on the road, and to have engaged in various types of risky driving. This group (the majority of whom were female) also tended to spend more time driving (in total, and at the weekend), and had experienced more crashes than other drivers (particularly property damage crashes when passengers were present).

There was considerable similarity in the road safety experiences and behaviours of those who had been involved in multiple crashes, engaged in high-level speeding, or driven when fatigued. However, some unique differences were found. For instance, while higher levels of driving exposure (time on the road) were linked with high-level speeding and fatigued driving, they were not associated with crash involvement. Similarly, length of time that licences had been held was associated with crash involvement but not the other two outcomes.

Individuals in each of the three problem driving outcome groups were often involved in another of the types of problem driving outcomes examined in this chapter, with overlap especially evident for multiple crash involvement and fatigued driving. High-level speeders were particularly likely to engage in the two other problem driving outcomes.

Some conclusions and implications that can be drawn from these findings are next presented.

Problematic driving did not occur in isolation

It was notable that problematic driving did not occur in isolation. Thus, young drivers who had been involved in multiple crashes, engaged in excessive speeding, or had driven when very tired on multiple occasions were more likely than other young drivers to have engaged in a wide range of risky driving behaviours and to have come to the attention of police for unsafe or illegal driving. Risky driving practices common to all three groups included low- and moderate-level speeding, falling asleep or nearly falling asleep when driving, driving when affected by alcohol and/or marijuana, and using a handheld mobile when driving. In addition, high-level speeders and fatigued drivers had been in more crashes than other drivers.

These findings are consistent with past research that has demonstrated strong links between the three problematic driving outcomes examined here and a range of other risky driving practices (see Clarke et al., 2002; Engström et al., 2003). There is also consistency with research showing associations between speeding and higher rates of driving offences (Palamara & Stevenson, 2003; Steptoe et al., 2004; Williams et al., 2006). Earlier findings from this report (Chapter 5), which showed that drink-drivers also more often engaged in a wide range of other risky driving practices, corroborate the view that problematic driving behaviours are interrelated and may reflect a risk-taking approach to driving among a sub-group of young drivers.

The overlap found is somewhat at odds with popular perceptions. Crashes tend to be viewed as inadvertent "accidents", while driving when fatigued is often seen as an outcome of a busy lifestyle. While this may be true, the consistent relationships found between these problem driving outcomes and other risky driving practices also suggest a more risky, unsafe approach to driving may be present among some.

The inter-connectedness of many problem driving behaviours reported here supports the viability of interventions aimed at a range of unsafe and/or unlawful driving practices since they will target the same individuals to a large extent. For example, the strong overlap found between high-level speeding and the other problem driving outcomes suggests that road safety efforts targeting excessive speeding may decrease crash involvement and fatigued driving as well. Nevertheless, as the overlap is not complete, more targeted approaches aimed at specific road safety behaviours will still be vital.

Risky driving was linked to other driving experiences

Young people who drove when fatigued were found to spend longer periods on the road than other drivers, spending more hours each week driving at night and during the day, both on weekdays and weekends. Other Australian research on fatigued driving among young people reveals similar trends (Harrison, 2006). Based on a telephone survey of 400 young drivers aged 18 to 25 years and on focus groups undertaken with drivers identified as at-risk drivers through a telephone survey, Harrison concluded that fatigued driving appeared to be a consequence of lifestyle-related motivational factors that overrode young people's concerns about the potential negative consequences of driving when fatigued. Respondents believed that the effects of tiredness on driving were manageable except at the most extreme levels and that they could habituate to tiredness with experience. As a result of these findings, the Royal Automobile Club of Victoria developed a campaign to address the issue of fatigue among young drivers. Other research shows similar trends (Connor et al., 2002; Stutts et al., 2003), and reinforces the continuing need for road safety education programs aimed at raising awareness of the risks of driving for long periods without a break.

Similarly, 23-24 year olds who engaged in high-level speeding also spent more time driving, particularly at night (on weekdays and weekends) and on weekends (during daytime and night-time hours); the peak times at which speeding, and speed-related crashes typically occur (Harrison et al., 1998; Liu et al., 1997). These trends, and those of other research, support enforcement activities that take place at night or on weekends to detect and deter young drivers who speed excessively.

Turning now to the crash history of the ATP sample overall, 43% had experienced a crash at 19-20 years of age, and this had risen to 60% by 23-24 years, indicating that most crashes had occurred when the cohort were less experienced drivers. Likewise, the average number of crashes experienced had risen from 1.36 to 1.6 over this time period. These findings are consistent with past research, which has linked driver inexperience to heightened rates of crash involvement (Cavallo & Triggs, 1996; Engström et al., 2003; Triggs & Smith, 1996). Nevertheless, after almost 6 years of licensure, 40% of the ATP sample had not experienced a crash when driving, and a similar percentage had not been detected speeding.

There were gender differences in risky driving behaviours

The three problematic driving outcome groups differed in gender composition. While most high-level speeders were males (70%), two-thirds of fatigued drivers were females, and similar numbers of males and females had experienced multiple crashes.

These findings align with past research with regard to speeding, as a large body of research shows that males are more likely to speed, be detected speeding, and be involved in speed-related crashes (Engström et al., 2003; Harrison et al., 1998; Liu et al., 2005; Palamara & Stevenson, 2003; Smart & Vassallo, 2005). Further, as described earlier (Chapter 3), a higher percentage of the young men in the ATP sample had engaged in all levels of speeding at 23-24 years than young women. Young men had also been detected speeding approximately twice as often as their female counterparts. These findings reinforce the need for specific initiatives aimed at reducing speeding among young men.

One such initiative is the "anti-hoon" laws introduced by several Australian states, including the state of Victoria in 2006. These appear to have had success in reducing excessive speeding and similar unsafe driving practices. In Victoria, vehicles can be impounded if a driver is detected exceeding the speed limit by 45 km/h. The legislation also applies to offences such as organising or engaging in street racing, evading police, loss of traction (e.g., burnouts, donuts, fish tails), dangerous driving or the repeated occurrence of driving while disqualified. Figures show that young males aged 18-25 years were the most likely group to have their cars impounded. Three years after the introduction of this law, Victorian statistics show that just 5% of those whose cars had been impounded re-offend for a second time and fewer than 1% have had their cars permanently confiscated (Department of Justice, 2009).

Our finding that the majority of fatigued drivers were female appears to be at odds with other research showing that male drivers are more often involved in fatigue-related crashes (Dobbie, 2002; Engström et al., 2003; Pack et al., 1995). However, this comparison is not straightforward, as the circumstances being compared are not the same. The current study looked at fatigued driving quite broadly and did not limit this to the occurrence of crashes, unlike many other studies. Studies that have found a link between male gender and driver fatigue have typically focused on individuals who have been injured or killed in fatigue-related crashes. The current study focused on young people who reported driving when very tired on several occasions during their ten most recent trips. A recent Australian study found that sleep-deprived women were more aware of the impact of fatigue on their driving performance in a simulated driving exercise than sleep-deprived men (Baulk, Biggs, van den Heuvel, Reid, & Dawson, 2006). This finding may partially explain why fatigue-related crashes are higher among men.

Additionally, previous research has shown links between male gender and crash involvement (Cavallo & Triggs, 1996; Clarke et al., 2002; Engström et al., 2003; Vick, 2003), but this trend did not emerge in the current study. However, the focus of previous research has generally been on serious injury crashes, whereas our study looked at the characteristics of drivers involved in a wide range of collisions (ranging from property damage crashes to injury crashes). Almost all of our study members who had been in a crash when driving had experienced relatively minor collisions resulting in property damage. Very few (n = 30) had been involved in more serious crashes in which a person had been injured or killed. It is possible that if we had restricted our focus to more serious crashes, a different pattern of findings may have emerged. However, the small number of participants in our study who had been involved in crashes of this type did not allow this approach.

Overall, our findings demonstrate that risky driving occurs among young men and women alike, although speeding is more common among young men and fatigued driving among young women. Intervention and prevention efforts should therefore be directed to both audiences, although could usefully highlight speeding for young men and driver fatigue for young women.

Conclusions

The driving histories, current on-the-road experiences and risky driving practices of young people who had been involved in multiple crashes, high-level speeding or fatigued driving were explored, as was the degree of overlap between these three problem driving outcomes. Considerable similarity was found in the road safety experiences and behaviours of those who had been involved in each problem driving outcome, with higher rates of apprehension for driving-related offences, and engagement in a wide range of other risky driving practices evident. Further, there was considerable overlap across the three problem driving outcomes and it was common for young people to be involved in more than one type.

7. Family and personal influences on young drivers

Families play an important role in the driving behaviour of young people in terms of the attitudes and values they transmit, the role models they provide, and the direct involvement they have in young people's driving careers. Other Australian Temperament Project research has shown that young people in their mid-20s are still very much connected to their parents and value their parents' input, and that parents provide considerable advice and support to young people, both emotionally and practically (Vassallo, Smart, & Price-Robertson, 2009).

This chapter looks at two broad issues:

• the influence of parents on young drivers' vehicle purchase; and
• links between young drivers' personal characteristics and their driving behaviour.

Looking specifically at parental influences on young people's driving behaviour, research has shown parallels between parent's driving behaviour and that of their sons and daughters. For instance, a number of studies have shown that parents with a history of crashes and violations more often have children who become involved in crashes or violate road laws (Ferguson, Williams, Chapline, Reinfurt, & De Leonardis, 2001; Wilson, Meckle, Wiggins & Cooper, 2006). While these studies cannot speak to the reasons underlying these trends, it is likely that family attitudes and values as well as parental modelling are involved.

Another way in which parents may influence young people's driving behaviour is through the assistance they provide when their sons and daughters are learning to drive. In the ATP study, almost three-quarters of young learner drivers had practised driving with their parents on at least a weekly basis (Smart & Vassallo, 2005). Driving practice occurred despite the fact that young people and their parents commonly experienced stress and conflict during these practice sessions, with 78% of young adults and 86% of parents reporting some or a lot of stress. Thus, parents play a considerable role in helping young people acquire the skills needed for driving.

Parents may also influence the driving careers of their young adult children after their children have gained their licence. One way in which this may occur is through the advice and support parents provide when young people are purchasing a car. The scant research located on this issue comes from North America and focuses on parents of teenagers (Cammisa, Williams, & Leaf, 1999; Hellinga, McCartt, & Haire, 2007; Rivara, Rivara, & Bartol, 1998).

While these studies found that teenagers would most commonly be provided with a car already owned by the family, parents nominated a variety of factors that would influence their choice if they were purchasing a vehicle for their teenagers. In the study by Helinga et al. (2007), the most common factors selected were safety and reliability. When specifically questioned about the safety features the car should have, parents said driver airbags (78-83% across the three states involved in the study), front passenger airbags (52-67%), and antilock brakes (22-62%) were the most important features, while 7-12% said that they did not consider safety at all. The parents in Camissa and colleagues' study (1999) selected price (22%), teenager's preference (13%), and small size and manoeuvrability (10%) as the most important factors that would influence their choice. In contrast, Rivara et al. (1998) found that parents of teenagers undergoing driver education training thought the following factors would be important or very important: insurance costs (94%), price (87%), repair record (85%), fuel economy (77%), antilock brakes (73%), airbags (65%), other safety features (84%), and large size (42%). Other factors were less commonly nominated.

These findings shed light on the factors that are important when parents purchase a car for their teenager, and also provide an indication of the factors that parents of young adults in the twenties might consider important. However, once young people reach adulthood and move into employment, it is common for many to purchase their own vehicles. The role of parents in the choices young people make is relatively unknown. The present study sought to explore the factors that parents believed young people should consider when purchasing a vehicle, the factors they thought had actually been important, and the degree of influence parents thought they had exerted on the choices of their young adult children. We also looked at whether these aspects were related to young people's educational attainment, gender, type of occupation and residential location (metropolitan or non-metropolitan), as well as the quality of parent-young adult relationships and the financial support parents had given their 23-24 year old sons/daughters.

The second issue this section addresses is whether (a) personal strengths such as social skills, temperament style and similar attributes, and (b) lifestyle factors such as employment, relationships, and "settling down" are related to driving behaviour. It is well established that positive states such as optimism, life satisfaction and happiness; character strengths such as empathy, persistence and self-control; and connections to others, including partners, families, peers, communities and society (Seligman, Steen, Park, & Peterson, 2005), are associated with positive outcomes among young people (Schulenberg, Bryant, & O'Malley, 2004).

In terms of driving behaviour, much attention has focused on the personal characteristics of young problem drivers. It is known that young problem drivers tend to show higher aggression or hostility (Cavallo & Triggs, 1996; Ulleberg & Rundmo, 2003); more attentional difficulties (Barkley, Murphy, Dupaul, & Bush, 2002; Woodward, Fergusson, & Horwood, 2000); are more attracted to sensation-seeking; and more often hold attitudes favourable to "norm-defying" behaviour (Cavallo & Triggs, 1996; Ulleberg & Rundmo, 2003) than other young drivers.However, much less is known about the opposite side of the equation - whether particular personal attributes and strengths are associated with a low-risk, law-abiding approach to driving. Our first In the Driver's Seat report (Smart & Vassallo, 2005) found that low- and moderate-level risky drivers aged 19-20 years had higher social skills from late childhood onwards than high-level risky drivers, and the low-level group was higher than the moderate-level group on some aspects of social skills too. Similarly at 19-20 years, low-level risky drivers tended to be more civically minded and socially responsible than high-level risky drivers. While these findings suggest that the low-level group was more socially skilled, more striking were the lower personal capacities of the high-level group compared with other young drivers. There appears to be little other relevant research on this question, as the focus of much past research has been on young problem drivers rather than young people who drive safely.

Increased maturity is linked to a lower involvement in risky driving. Bingham and colleagues (2008) recently showed that greater psychosocial maturity gained through the taking on of adult roles, attitudes and behaviours was associated with lower rates of problem driving. Similarly, Jessor et al. (1997) argued that the decrease in risky driving that occurred between 18 and 25 years was related to the embracement of adult social roles, and greater behavioural and psychosocial "conventionality" (e.g., full-time employment, marriage). However, as noted in Chapter 4, early adulthood can be a period of considerable risk-taking, with antisocial behaviour, gambling and substance use relatively common at this age. Young people who engage in risk-taking or who have friends who are involved in risk-taking tend to also engage in risky driving (Beirness & Simpson, 1988; Shope & Bingham, 2002; Vassallo et al., 2008). These findings suggest links between young people's lifestyle preferences and their driving tendencies, with those who have moved into employment, are in a committed relationship, have become parents, or are not involved in other forms of risk-taking, being more likely to be safe drivers.

Thus, the second broad issue addressed in this chapter is whether positive personal attributes and lifestyle characteristics indicative of "settling down" are related to a safe, law-abiding approach to driving.

7.1 Family influences on young drivers' vehicle purchase

We look first at family influences on young drivers' vehicle purchases, with four issues investigated:⁹¹

• the factors that parents thought young people should consider when purchasing a vehicle;
• the factors parents thought had influenced their son/daughter's choice of vehicle;
• the degree of influence parents thought they had exerted on the choices of their young adult children; and
• whether parents' involvement in their son's or daughter's car purchase was related to the quality of their relationships, or to the provision of support.

Vehicle purchase: Factors parents thought young people should consider

Parents were asked whether their young adult children had bought a car since gaining their licence, and whether parents had helped to select the vehicle. A total of 814 young people (81% of the sample) had purchased a vehicle, and 544 parents (67% of parents whose son/daughter had purchased a vehicle) had helped with the selection of the vehicle. If parents had helped in the selection of a vehicle, they were then asked: "When providing advice and assistance to your son/daughter, what did you think should have been the three most important factors in the choice of his/her vehicle to purchase?" Parents were asked to choose three responses from the options listed in Table 25.

Note: Percentages add to more than 100% as multiple responses were obtained.

Most parents (84%) thought that price should be an important consideration in their son's or daughter's selection of a vehicle. Three-quarters selected reliability, while fuel economy and safety features were also ranked highly, with about 40% of parents choosing these options. Factors associated with the appearance, power, comfort, or special features of the car were of low importance as fewer than 5% of parents thought their son or daughter should consider these factors when deciding on a car to purchase.

The responses of parents of young men and of young women were compared to explore whether there were differences in the factors that parents thought should have been important in their son's or daughter's choices. While there were trends for significant differences on a number of aspects (price, type of vehicle, style/image, power/performance and safety features), these did not reach the adjusted significance level.⁹² However more parents of young women than young men (34% vs 16%) thought vehicle size should be important.⁹³

The responses of parents of young people living in metropolitan areas were compared with those of parents of young people living in non-metropolitan areas on this issue, with no significant differences being found. Similarly, parents' perceptions were not related to their sons'/daughters' educational attainment (classified as university, other post-secondary, or secondary only) or occupational status (percentile ranking on the ANU_4 Occupational Status classification system).

Vehicle purchase: Factors parents thought young people actually considered

All parents of young people who had purchased a vehicle since gaining their licence were asked which three factors they thought had been the most influential in their son or daughter's choice of vehicle. Their responses are shown in Table 25.

Price and reliability were the two most common responses (81% and 50% respectively), followed by style/image/appearance (32%), fuel economy (29 %) and size (27%). The other factors were selected by fewer than 20% of parents. While there were similarities between the factors parents believed should be important and those they thought had actually been important (e.g., price and reliability), there were some differences too (see Table 25). Few parents rated style/image/appearance, power/performance and vehicle type as factors that should be important, but many more believed that these factors had been influential in their son's/daughter's choice. On the other hand, parents tended to think safety features should have been an important consideration, but fewer believed it had been.

We again compared the responses of parents of young men and parents of young women to investigate gender differences (Figure 33). There were significant differences on five of the eleven factors (excluding other reasons). More parents of young women than young men thought reliability (trend), size, fuel economy and safety features had been important,⁹⁴ while more parents of young men than young women thought type of vehicle and power/performance had been important.⁹⁵

Figure 33. Factors parents believed their 23-24 year old children actually considered when purchasing a vehicle, by sons and daughters

There were no significant differences according to young people's residential location, educational attainment or occupational status.

Influence of parents on vehicle purchase

Parents who had helped their young adult children select a vehicle were asked to rate how much influence they thought they had exerted on their son's or daughter's choice. The great majority of parents thought they had some influence, with 58% perceiving that they had been somewhat influential, and close to another third feeling that they had been very influential (Table 26). Only 1% thought they had had no influence at all on their son's/daughter's car choice.

Parents of young women more often felt they had influenced their young adult child's choice of vehicle than did parents of young men (Figure 34). There were no significant differences between parents of young people living in metropolitan and non-metropolitan areas on the amount of influence parents thought they had exerted, or according to young people's educational attainment or occupational status.

Figure 34. Parents' perceptions of their influence on their 23-24 year old children's vehicle purchase, by gender of their child

Influence of parent-young adult child relationship on vehicle purchase

The next issue examined is whether the type of relationships between parents and young people, and the supports parents provided, were related to parental involvement in, and influence on, young men's/women's purchase of a car.

Using Pierce, Sarason and Sarason's Social Support Scale (1991), adapted for parent report, three aspects of parent-young adult relationships were measured (with a 5-point response format ranging from never to always):

• depth of relationship (e.g., he/she values the relationship between you);
• support (e.g., he/she counts on you for help with a problem); and
• conflict (e.g., he/she gets upset with you).

Financial assistance was measured by five items asking whether parents had provided help with bills or rent, a loan or gift of money, substantial material assistance (e.g., a car), education course fees, or other forms of financial support, using a yes/no response format. The number of differing forms of assistance provided was summed (possible range of 0 to 5).

Figure 35 shows that parents who helped with the selection of a vehicle tended to be more supportive, and had given greater financial assistance.⁹⁶ There was also a trend for them to perceive there to be greater depth in their relationships with their sons/daughters.⁹⁷ However, the differences were more of degree, as the average scores of the two groups were at the higher end of the scale on depth of relationship and support (between 3 and 4), indicating that good depth and support were generally from "sometimes" to "often" present. Similarly, the two groups' average scores on the number of differing types of financial assistance given by parents were considerably above 1, suggesting that most parents in the ATP sample had financially supported their young adult children in some way.

Figure 35. Depth of parent-young adult child relationship, support and financial assistance, by whether parents helped with vehicle purchase

Parents who thought they had influenced their son/daughter's vehicle choice tended to report better quality relationships with their young adult children (more depth, greater support) and there was a trend for them to have provided more financial assistance (Figure 36).⁹⁸

Figure 36. Depth of parent-young adult child relationship, support and financial assistance, by how much parents influenced vehicle purchase

7.2 Personal attributes, lifestyle characteristics and driving

The second issue addressed is whether positive personal attributes and lifestyle characteristics are associated with a less risky, law-abiding approach to driving.

To examine this issue, the low-, moderate- and high-level risky driving groups identified at 23-24 years were compared (Chapter 4). In summary, the low-level group showed the lowest levels of all types of risky driving at 23-24 years, although they had occasionally engaged in low-level speeding, fatigued driving and mobile phone use when driving. The moderate-level group was intermediate between the low- and high-level groups on the risky driving indicators and had shown frequent low-level speeding, as well as regular fatigued driving and mobile phone use when driving. The high-level group were frequent speeders and mobile phone users when driving, showed moderate levels of fatigued driving and non-seatbelt use, and also occasionally engaged in drink-driving and driving when affected by illegal drugs.

Personal characteristics of low-, moderate- and high-level risky drivers

The three risky driving groups were compared on the following characteristics:

• social skills (Smart & Sanson, 2003), reported by young people, with a 5-point scale ranging from never/almost never to always/almost always:
  • empathy - e.g., I try to be a kind and caring person; people come to me to share their problems;
  • assertiveness - e.g., I am considered to be a leader; I initiate conversations in groups;
  • responsibility - e.g., I fulfill my obligations; I am punctual in meeting task deadlines; and
  • self-control - e.g., I can assert my opinion without fighting or arguing; I accept constructive criticism;
• temperament style (Windle & Lerner, 1986), reported by parents about their young adult child, using a 5-point scale ranging from very untrue to very true:
  • sociability - e.g., enjoys meeting new people; tends to withdraw in new situations (reverse scored);
  • flexibility - e.g., can make him/herself at home anywhere; his/her first reaction is to reject something new or unfamiliar (reverse scored);
  • positive emotionality - e.g., his/her mood is cheerful; generally is happy;
  • persistence - e.g., persists at a task until it is finished; can stick with an activity for a long time;
  • negative reactivity - e.g., reacts intensely when frustrated; yells or snaps at people when angry;
  • distractibility - e.g., if he/she has to stay in one place for a long time, gets very fidgety; can always be distracted by something else, no matter what he/she might be doing; and
  • activity - e.g., is energetic; never seems to keep still;
• other personal attributes, reported by young people, with the same 5-point scale used for social skills:
  • perspective-taking (Davis, 1983) - e.g., I try to look at everybody's side of a disagreement before I make a decision; when I'm upset with someone, I try to put myself "in their shoes";
  • optimism (adapted from Rosenthal, Gurney, & Moore, 1981) - e.g., when I think about the future I feel optimistic; things usually turn out well for me;
  • identity clarity (adapted from Markstrom, Sabino, Turner, & Berman, 1997; Rosenthal et al., 1981) - e.g., I've got a clear idea of what I want to be; I know what kind of person I am;
  • autonomy (adapted from Chassin, Pitts, & DeLucia, 1999) - e.g., I am an independent type of person; I am comfortable doing things without the help or input of others; and
  • planfulness (ATP-devised scale) - e.g., I make and carry out long-term plans; I make detailed plans for what I want to achieve.

Low-level risky drivers showed more highly developed personal characteristics in several areas than other drivers, as indicated by Figure 37. Overall, there were significant differences on 3 of the 16 aspects assessed and trends for differences on another 6 aspects. Thus, low-level risky drivers were more empathic and responsible and showed greater perspective-taking than moderate-level and high-level risky drivers.⁹⁹ The aspects on which there were trends for differences were self-control, sociability, persistence, reactivity, capacity to plan for the future, and autonomy.¹⁰⁰ Once again, the group differences found were a matter of degree, as group means were generally around 4, indicating that these attributes were often present among members of all groups.

Figure 37. Personal characteristics, low-, moderate- and high-level risky drivers, at 23-24 years

Lifestyle characteristics of low-, moderate- and high-level risky drivers

Turning now to lifestyle characteristics, the three risky driving groups were compared on the following four areas of life, as reported by young people:

• interpersonal relationships:
  • relationships with parents (Pierce et al., 1991) - a composite of depth of relationship (e.g., your relationship with them is important to you), support (e.g., you can count on them for help with a problem) and conflict (e.g., they upset you) sub-scales, using a 5-point response format ranging from never to always;
  • relationships with siblings (Pierce et al., 1991) - parallel items as for relationships with parents;
  • relationships with friends (Pierce et al., 1991) - parallel items as for relationships with parents; and
  • extensiveness of friendship network (Stone & Hughes, 2002) - number of close friends and number of other friends, using the following categories: none, 1-2, 3-5, 6-10, 11-15 and 16 or more;
• romantic relationships:
  • closeness of relationship with partner (adapted from Braiker & Kelley, 1979) - e.g., I feel very attached to my partner; my partner encourages or helps me to do things that are important to me, using a 4-point response format ranging from rarely/never to always;
  • length of current relationship - total number of weeks in duration; and
  • length of longest committed relationship - total number of weeks in duration;
• educational attainment and occupational status:
  • educational attainment (ATP-devised ranking system) - 1 = postgraduate university degree; 2 = graduate diploma/certificate; 3 = bachelor university degree; 4 = diploma/advance diploma; 5 = certificate 3 or 4; 6 = certificate 1 or 2; 7 = other post-secondary qualification; 8 = Year 12; 9 = Year 11; 10 = Year 10; 11 = Year 9; 12 = Year 8; 13 = Year 7; 14 = primary schooling; and
  • occupational status (Jones & McMillan, 2001) - percentile ranking on the ANU-4 Occupational Status classification system;
• social and civic engagement:
  • involvement in social/community groups (Stone & Hughes, 2002) - number of differing groups participated in during the past 12 months (e.g., sports, recreation/hobby, arts/cultural, education/training, religious groups), with a range of 0 to 13;
  • civic engagement (Stone & Hughes, 2002) - number of differing civically oriented activities participated in during the past 12 months (e.g., volunteered, donated money, taken part in a demonstration/march, undertaken fundraising for charity, signed petition), with a possible range of 0 to 16;
  • trust in people (Stone & Hughes, 2002) - mean of 4 items (e.g., most people can be trusted; people will try to take advantage of you if they can; reverse scored), using a 5-point response format ranging from disagree completely to agree completely; and
  • tolerance (items from Household Income and Labour Dynamics of Australia study and ATP-devised items) - mean of 3 items (e.g., having people from different ethnic backgrounds makes Australia a better place; immigrants should change their values and behaviours to those of their new country; reverse scored, using same response format as trust in people.

A small number of significant differences were found on lifestyle characteristics, as shown in Figure 38, with differences evident on 2 of the 13 aspects and trends for differences on another 3 aspects. The low-level group had better quality relationships with parents and were more tolerant in their attitudes.¹⁰¹ There were also trends for differences on relationships with siblings and romantic partners and level of trust in others.¹⁰² There were no differences on the length of young people's current romantic relationships or their previous longest committed relationship. The three groups did not significantly differ on their educational attainment or current occupational status, or likelihood of taking part in civic activities or participation in community and other social groups.

Figure 38. Lifestyle characteristics, low-, moderate- and high-level risky drivers, at 23-24 years

7.3 Discussion and implications

This chapter explored two main issues on which there has been little previous research: the influence of parents on their young adult children's vehicle purchase, and connections between mid-twenty year olds' personal and lifestyle characteristics and their driving behaviour.

Approximately 80% of young people had purchased a car since gaining their licence, and close to two-thirds of their parents had helped with the choice of a vehicle. Of these parents, almost 90% thought they had influenced their son's/daughter's choice to some degree, with about 30% feeling they had had a large influence. Parents were more likely to have had an influence if relationships between the young people and their parents were close.

Parents also answered questions on the factors they thought their sons/daughters should have taken into account when selecting a vehicle, and the factors they thought had actually been important. Parents of young women more often selected aspects related to safety (e.g., size, safety features) as salient in their daughters' choices than parents of young men, while conversely parents of young men thought type of vehicle and power/performance had been stronger influences on their sons' choices.

Young people's personal characteristics were related to their driving style, with low-level risky drivers tending to be more empathic and responsible and to be able to see another person's point of view than moderate- and high-level risky drivers. They also tended to have better quality relationships with parents and to be more tolerant in their attitudes. However, their educational attainment, occupational status or involvement in a romantic relationship was not related to their driving behaviour.

Some implications of these findings are discussed next.

Parents influenced their son's/daughter's car purchase

Parents and families are still clearly influential in early adulthood. Not only did the majority of parents help their sons and daughters with their selection of a motor vehicle, young people almost always took notice of their parents' opinions. Closer relationships were linked to parents having greater influence on young people's choice of a vehicle. Additionally, our comparisons of low-, moderate- and high-level risky drivers showed that closer relationships between young people and their parents were related to a more law-abiding driving style. Together with other ATP findings showing that young people value their parents' input and feel that parents play an important role in their lives (Vassallo et al., 2009), these findings suggest that parents have a larger influence on young people than is commonly thought. Parents are not often considered in road safety efforts targeted at young drivers. However, given the continuing importance parents seem to have in the lives of their young adult children, there may be scope to make use of their influence, most obviously in relation to young people's purchase of a vehicle, but also in relation to young people's driving behaviour more generally.

In terms of car purchase, information could be directed at young people of driving age and at their parents as well. The resources already available are relevant for both groups; for example, the TAC's <www.howsafeisyourcar.com.au> website contains safety ratings for differing car types, fact sheets about buying a safe car and information about differing car safety features; and <www.racv.com.au> provides advice about buying and selling a car, information about the value of pre-purchase inspections and purchase recommendation reports. Some targeted campaigns could focus on encouraging parents to be involved in their sons'/daughters' car purchase, highlighting the characteristics that are important to consider when purchasing a car. As many young people may be purchasing second-hand cars, information on how to identify a safe, roadworthy used car would also appear valuable. The current findings support the value of such initiatives.

The mechanisms by which parents might influence their sons'/daughters' driving propensities remain poorly understood. The current findings cannot explain how a positive relationship with parents might lead to a lower involvement in risky driving. However, they echo earlier findings from this study (Smart & Vassallo, 2005), in which poorer parent-child relationships were found to be important precursors of risky driving and crash involvement at 19-20 years. It was thought that close parent-child relationships may have enabled parents to exert greater influence on young people's activities and friendship groups, decreasing their likelihood of becoming involved in risk-taking activities such as antisocial behaviour, substance use and risky driving. It is possible that close parent-young adult relationships may help maintain young people's avoidance of risk-taking, including risky driving.

Parents were more conscious of safety and roadworthiness than young people

While there were similarities in the factors that parents thought young people should have and did consider when selecting a vehicle to purchase, there were some disparities too. Unsurprisingly, price was the most common factor, with more than 80% seeing this as one of the three most important factors. Three-quarters of parents thought reliability should have been important; however only one half thought this had been a central issue in their son/daughter's choice. Similarly, almost four-tenths of parents believed safety features were important, whereas just over one-tenth thought this had been a major consideration for their young adult children. On the other hand, very few parents (5%) thought style/image/appearance should have been important, but almost one-third believed this had been an influential factor. Likewise, only 3% of parents thought power/performance should have been considered, whereas 12% rated this aspect as one of the most salient factors for their young adult children.

It is difficult to compare the current findings with those of other studies, as previous research has focused on the factors parents themselves would take into account when purchasing a vehicle for their teenager, whereas the current study looked at the factors that parents thought young people should have considered. There were some consistencies: for example, a similar percentage of parents selected price in the ATP study and in Rivara et al. (1998), while the proportion nominating safety was similar to Hellinga et al. (2007). However, more ATP parents selected reliability than the parents in Hellinga et al. (2007) and Camissa et al. (1999); fewer selected fuel economy than Rivara et al. (1998); and the proportion nominating size was larger than Camissa et al. (1999) but smaller than Rivara et al. (1998). As noted earlier, it is difficult to draw comparisons due to cultural differences (the other studies were from North America), differences in the age of the young people (the North American studies were of parents of teenagers while the current study was of parents of young adults) and differences in the vehicle purchaser (parents vs young people).

The current findings suggest that while some young people focused on safety and reliability when choosing a vehicle, others were also swayed by aesthetic and image factors. Parents seemed to be more conscious of safety and roadworthiness issues than young people. These findings reinforce the value of parents being involved in their sons'/daughters' vehicle purchase, as they can guide young people to give greater priority to safety and reliability. Research shows clear links between vehicle type (e.g., sedan, four-wheel drive, light commercial, sports cars) and size (large, medium, small) and rates of crashes, crash-related injuries and deaths, with sport utility vehicles (SUVs), sports cars and smaller vehicles being more frequently involved in these outcomes (e.g., Broughton, 2008; Newstead, Cameron, & Watson, 2004; Wenzel & Ross, 2005). Further, in recognition of the dangers that high-powered cars pose to young drivers, the Australian states of Victoria, New South Wales and Queensland have brought in restrictions to prevent probationary licence holders from driving high-performance vehicles. One implication of these restrictions is that the purchase of high-performance vehicles by young people should be discouraged. Overall, the current findings suggest that initiatives to inform young people's vehicle choice remain relevant and necessary.

There were gender differences in the factors that influence vehicle purchase

When considering a vehicle to purchase, young men were more attracted by vehicle type and power/performance than young women. Power/performance has been linked to a higher risk of crash involvement among young novice drivers (Senserrick & Haworth, 2005). These findings suggest that young men give less attention to safety and reliability when selecting a vehicle than young women, and are more oriented towards car attributes that may decrease their safety on the road. Interestingly, while few parents thought type of vehicle, style/image/appearance and power/performance should have been major considerations in the choice of vehicle, more parents of young men thought these factors should be relevant than did parents of young women. Thus, there may be cultural acceptance for young men to value these aspects.

As seen earlier in Chapter 3, there were gender differences in rates of risky driving. Young men exceeded the speed limit (especially at the higher speeding categories of 11-25 km/h over the limit and more than 25 km/h over), drove without a seatbelt, and drove when affected by alcohol more often in their ten most recent trips than young women. Further, the small group of high-level risky drivers contained more males than females (58% vs 42%). The combination of risky driving with a high-performance vehicle is a potentially lethal combination. These findings support the importance of road safety efforts targeting the attitudes of young men (and to a lesser extent their parents) towards vehicle choice.

However, it must be acknowledged that it may not be easy to change the attitudes of young men, as Australian culture tends to place high value on car type and motor sports, particularly among males. Examples of this are the stereotypes of young men being "Ford" or "Holden" drivers, the mass appeal of motoring events, and car advertising that shows vehicles being driven in extreme conditions, which appeals to young people's thrill-seeking tendencies. Thus, efforts to change societal perceptions will remain essential.

Personal characteristics were linked to levels of risky driving

Our comparisons of low-, moderate- and high-level risky drivers showed that a low-risk, safe approach to driving was associated with more positive characteristics in several areas of life. Thus, the low-level group tended to be more empathic and responsible and able to see another person's point of view. Empathy and the ability to see another's point of view are likely to facilitate tolerance towards other drivers or incidents that occur on the road, while being responsible may facilitate a careful and cautious approach to driving. These findings are a reminder that what an individual is like as a person can affect his/her behaviour behind the wheel. They point to the value of helping young people gain an understanding of their inherent tendencies and how these might influence their day-to-day behaviour, including their approach to driving. Once individuals have gained an understanding of their personal tendencies, they can be assisted to develop strategies to manage these tendencies when driving.

The findings extend our earlier findings, showing that low-level risky drivers identified at 19-20 years had displayed higher social skills from late childhood onwards than moderate- and high-level risky drivers. These differences were still evident four years later at 23-24 years. They are also consistent with other research indicating that "character strengths", such as empathy, persistence and self-control (Seligman et al., 2005), are linked to positive outcomes among young people (Schulenberg et al., 2004).

The comparisons also revealed that the moderate-level group was rather similar to the high-level group in terms of their personal characteristics. The moderate-level group tends to be overlooked, but does pose a road safety concern, given that this group did engage in some risk-taking on the road, and was much more numerous than the high-level group (261 vs 54).

Lifestyle characteristics may be linked to level of risky driving

We also sought to determine whether having supportive relationships with others, being more "settled" psychologically, and being connected to society through prosocial attitudes or involvement in community and civic activities would be associated with a more law-abiding approach to driving. Only some of these characteristics differentiated the low-, moderate- and high-level risky driving groups, such as better quality relationships with parents and tolerant attitudes. However, engagement in community or civic activities was not related to driving behaviour, nor was "settling down", as indexed by occupational status, educational attainment or romantic relationship history. Thus, at this stage of life, young people's driving behaviours were to some extent related to their interpersonal relationships and attitudes/values, but not to their material circumstances, level of maturity, or civic engagement.

There are some consistencies with other research indicating that young people's connections to others, including partners and families are associated with positive outcomes (Seligman et al., 2005) and with previous ATP findings showing that there were more parent-child relationship difficulties among 19-20 year old high-level risky drivers compared with low-level risky drivers (Smart & Vassallo, 2005). However, there are inconsistencies with research indicating that as young people mature and begin to adopt adult roles, they are less involved in risky driving (Jessor et al., 1997), since our indicators of "settling down" did not differentiate between the low-, moderate- and high-level risky driving groups. As noted in Chapter 4, the differing pattern of results found here may reflect "era effects" (i.e., differences between young people living in the 2000s vs those living in the 1990s or earlier), or cultural effects (the other research on this issue comes from North America), such as different attitudes towards risky driving, values concerning appropriate behaviour on the road, and tolerance for acts such as drink-driving.

Conclusions

This chapter examined two issues on which there has been very little research to date: (a) the influence of parents on young people's vehicle purchase; and (b) connections between 23-24 year olds' positive personal characteristics, lifestyle and driving behaviour. Most parents had played a role in their sons'/daughters' vehicle choice, and this was more likely if relationships between parents and their young adult children were close. The importance of involving parents in young people's vehicle purchase was highlighted. A low-risk, law-abiding approach to driving was associated with qualities such as empathy, responsibility and perspective-taking, as well as closer connections to parents and more tolerant attitudes.

8. Overview

This second report from the collaboration between the Australian Institute of Family Studies, the Transport Accident Commission of Victoria and the Royal Automobile Club of Victoria examined a range of issues relating to the driving behaviour of a community sample of young Australian drivers aged in their mid-20s.

Six main issues were examined:

• the driving behaviours and driver histories of young people aged in their mid-20s;
• the stability of driving behaviour over young adulthood (between the ages of 19-20 to 23-24 years);
• links between risky driving and substance use;
• the co-occurrence of crash involvement, high-level speeding, fatigued driving and other aspects of road safety among drivers in their mid-20s;
• the influence of families on young people's car purchases; and
• connections between 23-24 year olds' personal characteristics and their driving behaviours.

As the findings and their implications for road safety practice have been discussed in detail earlier in this report, they will not be further discussed in depth here. Rather, this section aims to provide an overview of several main themes emerging from this research, as well as identifying possible areas for further research using data from the Australian Temperament Project.

8.1 Stability and change in risky driving over young adulthood

The first In the Driver's Seat report examined the learner driver experiences and current driving behaviour of more than 1,100 young drivers (aged 19-20), who had been driving, on average, for approximately one year and nine months. This second report has built upon these findings to provide further insights into the changing nature and incidence of different driving practices as young people move beyond the early years of their driving careers, and increase in maturity and driving experience.

The first report established that unsafe driving behaviours, such as speeding and driving when fatigued, were relatively common among 19-20 year old drivers. Analysis of data collected when the young people in the study were aged 23-24 indicates that these and other types of risky driving were still widespread among drivers in their mid-20s. For example, low-level speeding, driving when fatigued, and mobile phone use while driving were highly prevalent among drivers of this age, and drink-driving was a growing problem. Furthermore, while there had been a modest decrease in rates of moderate- and high-level speeding over the early adult years, the frequency of moderate-level speeding at age 23-24 was still concerning. Driving under the influence of illegal drugs and the non-use of seatbelts were less of an issue among this sample of young Victorian drivers, which is perhaps not surprising considering the low incidence of illegal substance use (other than marijuana) among this sample at this age, and the fact that Victoria, Australia, was the first state in the world to introduce compulsory seatbelt use legislation.

When viewed in conjunction with other findings from this second report, these results suggest that engagement in risky driving remained fairly stable between the ages of 19-20 and 23-24 years. For example, while overall sample trends indicated a modest reduction in some forms of risky driving over this four-year period, and some individuals showed a decrease in their risky driving tendencies over this time, the frequency of risky driving was generally similar at both ages. These findings suggest that risky driving continues to be a serious road safety issue for drivers in their mid-20s, emphasising the importance of sustaining road safety efforts beyond the early driving years. Given the high prevalence of speeding, fatigued driving, mobile phone use and drink-driving among 23-24 year old drivers, initiatives targeted at these risky driving practices would appear to be of particular value for this age group.

Nevertheless, despite the relative stability of risky driving across the sample from the late-teens into the mid-20s, the findings of this report also show there was capacity for change in individual driving patterns over this period. For instance, many who frequently took risks on the road at age 19-20, no longer did so at 23-24, whereas, conversely, risky driving emerged as a significant problem for a small number in their mid-20s.

On a positive note, the findings of this research also suggest that avoidance of risky driving during the early years of young people's driving careers may stand them in good stead, as very few young people who fell into this group later engaged in high levels of risky driving. While small group numbers prevented us from undertaking further analyses to determine the factors that may have contributed to persistence or change in driving patterns across early adulthood, this is clearly an issue that would benefit from further research.

8.2 Co-occurrence of different problem behaviours

Another issue addressed in the first report was the extent to which risky driving occurred in conjunction with other types of problem behaviour. This issue was taken up again in this report, but as well as focusing on the degree of overlap between risky driving and other problem behaviours (in this case, substance use), the interconnectedness of different forms of risky driving (e.g., speeding and drink-driving) was also examined.

The first report found substantial overlap in the precursors of risky driving, substance use and antisocial behaviour. In addition, rates of substance use and antisocial behaviour were found to be higher among high-level risky drivers than among those who engaged in low or moderate levels of risky driving at age 19-20. These findings were seen as offering partial support for the view that problem behaviours are interrelated, and may be caused by a common propensity or trait for risk-taking.

The findings of the second report further support this notion, showing a strong link between risky driving and substance use among drivers in their mid-20s. For instance, 23-24 year olds who frequently took risks on the road were more likely than their more law-abiding counterparts to binge drink and use marijuana, ecstasy and/or amphetamines. They were also more likely to use multiple legal and illegal substances.

The current findings also extend those of the first report by providing evidence to suggest that different forms of risky driving are interrelated, with drink-drivers, high-level speeders and fatigued drivers exhibiting higher rates of other problematic driving behaviours than other drivers at 23-24 years. In particular, the co-occurrence of high-level speeding with other forms of risky driving was notable.

These findings support the utility of intervention approaches that address a range of unsafe and/or unlawful driving practices as a valuable supplement to specifically targeted road safety initiatives.

8.3 Personal influences on young drivers

The first report highlighted the important contribution that personal factors can make to a driver's behaviour on the road. For instance, 19-20 year olds who exhibited different problematic driving outcomes (high-level risky driving, involvement in multiple crashes, multiple speeding violations) could be differentiated from other drivers on a range of individual attributes and behaviours during adolescence and early adulthood. These findings were seen as an important reminder that the attributes and capacities that a young person brings to the task of driving can influence their skills and effectiveness as drivers, just as can factors associated with the driving environment.

The findings of the second report reinforce these earlier findings, demonstrating a link between personal characteristics and driving style among drivers in their mid-20s. For instance, comparisons of young people who engaged in low, moderate and high levels of risky driving at 23-24 years, showed that low-level risky drivers had more highly developed personal characteristics in several areas than moderate- and high-level risky drivers, especially in terms of their levels of empathy and responsibility and their ability to see others' points of view. These capacities may help them to respond calmly and responsibly when driving.

One personal characteristic that emerged as a particularly powerful contributor to road safety behaviour, at both 19-20 and 23-24 years, was gender. The majority of high-level risky drivers at both ages were male, and males were consistently over-represented among those who sped, did not wear a seatbelt when driving, or drove when affected by alcohol. In addition, young men had more often experienced trouble with the law as a result of their driving behaviour at both ages. While females generally took fewer risks on the road, there were some risky practices that they tended to engage in more often than males (e.g., driving when fatigued).

Gender differences were not only evident in the behaviour of young men and women on the road, but also in the approaches they used to avoid drink-driving (females were more likely to abstain from drinking; males were more likely to alter their drinking habits, drink less, count or space their drinks, or consume low alcohol beer); the factors they considered important when purchasing a motor vehicle (e.g., males placed higher value on vehicle type and power/performance); and the driving practices of their friends and romantic partners (males were more likely to have friends who were drink-drivers, while females were more likely to report their partner was a drink-driver). These findings suggest that a gender-focused approach to road safety may be beneficial, to address the differing factors that characterise or are related to risky driving among young men and young women.

8.4 Social influences on driving behaviour

The findings of the first and second reports also demonstrate the significant influence that social factors may have on a young person's driving behaviour. For instance, the first report found that young people who went on to become problematic drivers at 19-20 years had typically experienced greater school adjustment difficulties and more problematic interpersonal relationships during adolescence than other young drivers.

A number of findings from the second report also point to the important role that social factors, and more particularly interpersonal relationships, may have on driving. As an example, the second report shows that parents generally played an important role in young adults' car purchases, with over two-thirds assisting their young adult children with their choice of motor vehicle, and most feeling that their advice had influenced their son's or daughter's decision to some degree. This was particularly true if parents shared close relationships with their adult children. Social factors also differentiated young people who engaged in low levels of risky driving from other drivers, with this group tending to have better quality relationships with parents at age 23-24, and more tolerant attitudes than those who engaged in higher levels of risky driving behaviour.

These findings reinforce the relevance of young people's personal qualities and broader life experiences to their behaviour as drivers. The findings from both reports highlight the importance of being connected to others as a deterrent of risky driving. The development and maintenance of adaptive interpersonal relationships with parents seemed particularly crucial and there may be scope for road safety programs to highlight and utilise parents' influence.

8.5 Levels of risk

The findings clearly highlight the road safety risk posed by the high-level risky driving group, both at 19-20 and 23-24 years. Considerable discussion of their personal attributes, circumstances and driving practices has been provided, as well as the type of road safety intervention and prevention strategies that may be most appropriate for this group. Both reports have also drawn attention to the increased risk posed by the moderate-level group; for example, these drivers had more often than low-level risky drivers been involved in antisocial behaviour and substance use from mid-adolescence to 19-20 years, and similar trends were found at 23-24 years with regard to substance use (overlap with antisocial behaviour was not examined at this latter age). Further, at 23-24 years, the moderate-level group showed similar levels of difficulties as the high-level group on personal characteristics.

The moderate-level group may be overlooked but does present a road safety concern, given that this group did engage in risk-taking on the road, and was much larger in size than the high-level group. While the high-level group presents the highest and most immediate risk, the moderate-level group may be more amenable to change, and achieving a reduction in their risky driving behaviour may result in greater gains for road safety. These findings point to the importance of targeting both the high- and moderate-level risky driving groups in road safety efforts.

8.6 Next phase of this research

The first and second reports have provided an in-depth account of the nature, prevalence and development of "normal" and "problematic" driving patterns among a large sample of young Australians and have yielded many valuable insights. Nevertheless, there remain several opportunities to exploit the road safety data contained in the unique Australian Temperament Project dataset. Further exploration of the data collected at ages 19-20 and 23-24, as well as the possible collection of a third wave of data when participants are in their late twenties could enable the investigation of issues such as:

• the stability of driving behaviour from the late teens to the late twenties;
• a qualitative, person-focused analysis of the characteristics of individuals whose driving profiles have changed over time;
• the longitudinal precursors of drink-driving from the earliest years of life;
• the effectiveness of differing strategies used by young people to avoid drink-driving;
• links between parents' road safety attitudes and behaviour and that of their sons/daughters; and
• connections between young drivers' attitudes to road safety issues and their driving behaviour.

Exploration of these issues would further add to our understanding of the road safety attitudes and behaviours of young Australian drivers.

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List of tables

• Table 1. Road safety questions and response categories, ATP Young Adult Survey, 2006
• Table 2. Road safety questions and response categories, ATP Parent Survey, 2006
• Table 3. Type of licence(s) ever held, at 23–24 years
• Table 4. Type of licence(s) currently held, at 23–24 years
• Table 5. Average number of hours spent driving, at weekdays and weekends and during daylight and night-time hours, at 23–24 years
• Table 6. Number of crashes experienced over driving careers, at 23–24 years
• Table 7. Number of times detected speeding over driving career, at 23–24 years
• Table 8. Risky driving behaviours during previous ten trips, at 23–24 years
• Table 9. Number of days in the past month of driving when near or over the legal alcohol limit, at 23–24 years
• Table 10. Number of friends who drive after drinking, at 23–24 years
• Table 11. Agreement that partner drives after drinking, at 23–24 years
• Table 12. Use of strategies to avoid drink-driving in past month, at 23–24 years
• Table 13. Risky driving sub-groups, at 19–20 years
• Table 14. Risky driving sub-groups, at 23–24 years
• Table 15. Risky driving patterns, 2- to 5-cluster solutions, at 23–24 years
• Table 16. Gender composition of risky driving groups, at 23–24 years
• Table 17. Level of subsequent risky driving behaviour among 19–20 year old risky driving cluster groups
• Table 18. Engagement in risky driving during their past 10 trips, drink-drivers and other drivers, at 23–24 years
• Table 19. Definitions and sizes of multi-substance use groups, at 23–24 years
• Table 20. Engagement in risky driving during their past ten trips, zero, single and multiple crash groups, at 23–24 years
• Table 21. Engagement in risky driving during their past ten trips, high-level speeders and other drivers, at 23–24 years
• Table 22. Engagement in risky driving during their past ten trips, fatigued drivers and other drivers, at 23–24 years
• Table 23. Road safety characteristics associated with problematic driving outcomes, at 23–24 years
• Table 24. Co-occurrence of multiple crashes, high-level speeding and fatigued driving, at 23–24 years
• Table 25. Factors parents believed their 23–24 year old children should consider and actually considered when purchasing a vehicle
• Table 26. Parents’ perceptions of their influence on their 23–24 year old children’s vehicle purchase

List of figures

• Figure 1. Number of hours typically spent driving per week, at weekdays and weekends and during daylight and night-time hours, at 23–24 years
• Figure 2. Frequency of making plans to avoid drink-driving, at 23–24 years
• Figure 3. Frequency of drink-driving after making plans to avoid it, at 23–24 years
• Figure 4. Engagement in risky driving during previous ten trips, males and females, at 23–24 years
• Figure 5. Frequency of plans being made to avoid drink-driving, males and females, at 23–24 years
• Figure 6. Frequency of engaging in drink-driving after making plans to avoid it, males and females, at 23–24 years
• Figure 7. Strategies used to avoid drink-driving, males and females, at 23–24 years
• Figure 8. Strategies used to avoid drink-driving, metropolitan and non-metropolitan young drivers, at 23–24 years
• Figure 9. Frequency of drink-driving after making plans to avoid it, low-, average- and high-status occupations, at 23–24 years
• Figure 10. Type of licence held by secondary, other post-secondary and university groups, at 23–24 years
• Figure 11. Frequency of drink-driving after making plans to avoid it, secondary, other post-secondary and university groups, at 23–24 years
• Figure 12. Actions taken to avoid drink-driving, secondary, other post-secondary and university groups, at 23–24 years
• Figure 13. Engagement in risky driving during previous ten trips, at 19–20 and 23–24 years
• Figure 14. Frequency of risky driving behaviours, at 19–20 and 23–24 years
• Figure 15. Engagement in risky driving behaviours at 23–24 years, by whether engaged in by the same individuals at 19–20 years
• Figure 16. Frequency of engagement in risky driving behaviours by the same individuals, at 19–20 and 23–24 years
• Figure 17. Frequency of risky driving behaviours, 19–20 and 23–24 year old risky driving sub-groups
• Figure 18. Frequency of risky driving behaviours, low-level risky driving group, at 19–20 and 23–24 years
• Figure 19. Frequency of risky driving behaviours, moderate-level risky driving group, at 19–20 and 23–24 years
• Figure 20. Frequency of risky driving behaviours, high-level risky driving group, at 19–20 and 23–24 years
• Figure 21. Frequency of risky driving behaviours, three-cluster groups, at 23–24 years
• Figure 22. Percentage who exceeded the speed limit at least once during their past 10 trips, drink-drivers and other drivers, at 23–24 years
• Figure 23. Percentage who had not worn a seatbelt for part or all of at least one recent trip, drink-drivers and other drivers, at 23–24 years
• Figure 24. Percentage who had driven when fatigued at least once during their past 10 trips, drink-drivers and other drivers, at 23–24 years
• Figure 25. Percentage who had driven when affected by an illegal drug at least once during their past 10 trips, drink-drivers and other drivers, at 23–24 years
• Figure 26. Percentage who had used a mobile phone when driving at least once during their past 10 trips, drink-drivers and other drivers, at 23–24 years
• Figure 27. Engagement in high- and very high-level binge drinking in the past month, low-, moderate- and high-level risky drivers, at 23–24 years
• Figure 28. Number of substances used in the past month, ATP sample, at 23–24 years
• Figure 29. Frequent multi-substance use in the past month, ATP sample, at 23–24 years
• Figure 30. Frequent multi-substance use in the past month, high-, moderate- and low-level risky drivers, at 23–24 years
• Figure 31. Frequent binge drinking and marijuana use in the past month, high-, moderate- and low-level risky drivers, at 23–24 years
• Figure 32. Number of hours spent driving, at weekdays and weekends and during daylight and night-time hours, fatigued drivers and other drivers, at 23–24 years
• Figure 33. Factors parents believed their 23–24 year old children actually considered when purchasing a vehicle, by sons and daughters
• Figure 34. Parents’ perceptions of their influence on their 23–24 year old children’s vehicle purchase, by gender of their child
• Figure 35. Depth of parent–young adult child relationship, support and financial assistance by whether parents helped with vehicle purchase
• Figure 36. Depth of parent–young adult child relationship, support and financial assistance, by how much parents influenced vehicle purchase
• Figure 37. Personal characteristics, low-, moderate- and high-level risky drivers, at 23–24 years
• Figure 38. Lifestyle characteristics, low-, moderate- and high-level risky drivers, at 23–24 years