Excellent gamer, excellent driver? The impact of adolescents' video game playing on driving behavior: a two-wave panel study

This study explored the impact of adolescents’ playing of racing and drive’em up games on their risky driving behavior. Participants were 354 adolescent boys and girls who took part in a longitudinal panel survey on video game playing and risk taking attitudes, intentions and behaviors. In line with cultivation theory and theory of planned behavior the results showed that (even after controlling for aggression and sensation seeking) video game playing during adolescence succeeded in predicting later risky driving behavior through adolescents’ attitudes and intentions to exhibit this behavior in the future. The results suggest that this relationship may in part be explained by the game content.     

The influence of anger,impulsivity, sensation seeking and driver attitudes on risky driving behaviour among post-graduate university students in Durban,South Africa

Introduction

Road traffic accidents (RTAs) constitute a serious global health risk, and evidence suggests that young drivers are significantly overrepresented among those injured or killed in RTAs. This study explores the role of anger, impulsivity, sensation seeking and driver attitudes as correlates for risky driving practices among drivers, drawing comparisons between age and gender.

Method

The study used a cross-sectional survey design, with a sample of 306 post-graduate university students from two universities in Durban, South Africa, who completed the self-administered questionnaire.

Results

The results indicate that drivers with higher driver anger, sensation seeking, urgency, and with a lack of premeditation and perseverance in daily activities were statistically more likely to report riskier driving acts. Males reported significantly more acts of risky driving behaviour (RDB) than females. Driver attitudes significantly predicted self-reported acts of RDB on most indicators. Older drivers (25 years and older) had safer driver attitudes and a lower sense of sensation seeking and urgency in life.

Conclusion

Interventions targeting young drivers, which focus on impeding the manifestation of anger, impulsivity and sensation seeking are recommended. Also, the empirical support for the attitude–behaviour hypothesis evidenced in this study vindicates the development or continuation of interventions that focus on this dynamic.     

Trajectories of kinematic risky driving among novice teenagers

Objectives

Elevated gravitational force event rates are associated with the likelihood of a crash or near crash and provide an objective measure of risky driving. The purpose of this research is to examine the patterns over time of kinematic measures of risky driving among novice teenage drivers.

Methods

Driving data were collected from 42 newly licensed teenage drivers during the first 18 months of licensure. Data recording systems installed in participants’ vehicles provided information on driving performance and driver characteristics. Latent class and logistic regression models were used to analyze trajectories of elevated gravitational-force (g-force) event rates, called kinematic risky driving, with respect to risk groups and associated factors.

Results

Kinematic risky driving over the 18-month study period was best characterized as two classes, a higher-risk and a lower-risk class. The rate of kinematic risky driving during the first 6 months generally maintained over 18 months. Indeed, of those classified by latent class analysis as higher risk, 88.9%, 94.4% and 94.4% had average event rates above the median in the 1st, 2nd, and 3rd 6-month periods, respectively, indicating substantial tracking over time. Friends’ risky driving, friends’ risky behavior, self-reported risky driving, and perceptions about risky driving and driving privileges were associated with trip-level rates of kinematic risky driving. However, none of these factors was associated with trip-level rates after stratifying by overall risk in a latent class model, although friend's risky driving was marginally significant.

Conclusion

Kinematic risky driving tended to track over time within the lower and higher risky driving groups. Self-reported risky driving and having risky friends were predictors of kinematic risky driving rates, but these variables did not explain the heterogeneity within higher and lower classes of risky drivers.     

Confirmatory factor analysis of the Behaviour of Young Novice Drivers Scale (BYNDS)

Purpose

The greatly increased risk of being killed or injured in a car crash for the young novice driver has been recognised in the road safety and injury prevention literature for decades. Risky driving behaviour has consistently been found to contribute to traffic crashes. Researchers have devised a number of instruments to measure this risky driving behaviour. One tool developed specifically to measure the risky behaviour of young novice drivers is the Behaviour of Young Novice Drivers Scale (BYNDS) (Scott-Parker et al., 2010). The BYNDS consists of 44 items comprising five subscales for transient violations, fixed violations, misjudgement, risky driving exposure, and driving in response to their mood. The factor structure of the BYNDS has not been examined since its development in a matched sample of 476 novice drivers aged 17–25 years.

Method

The current research attempted to refine the BYNDS and explore its relationship with the self-reported crash and offence involvement and driving intentions of 390 drivers aged 17–25 years (M = 18.23, SD = 1.58) in Queensland, Australia, during their first 6 months of independent driving with a Provisional (intermediate) driver's licence. A confirmatory factor analysis was undertaken examining the fit of the originally proposed BYNDS measurement model.

Results

The model was not a good fit to the data. A number of iterations removed items with low factor loadings, resulting in a 36-item revised BYNDS which was a good fit to the data. The revised BYNDS was highly internally consistent. Crashes were associated with fixed violations, risky driving exposure, and misjudgement; offences were moderately associated with risky driving exposure and transient violations; and road-rule compliance intentions were highly associated with transient violations.

Conclusions

Applications of the BYNDS in other young novice driver populations will further explore the factor structure of both the original and revised BYNDS. The relationships between BYNDS subscales and self-reported risky behaviour and attitudes can also inform countermeasure development, such as targeting young novice driver non-compliance through enforcement and education initiatives.     

Speeding by young novice drivers: What can personal characteristics and psychosocial theory add to our understanding?

Purpose

Young novice drivers continue to be overrepresented in fatalities and injuries arising from crashes even with the introduction of countermeasures such as graduated driver licensing (GDL). Enhancing countermeasures requires a better understanding of the variables influencing risky driving. One of the most common risky behaviours performed by drivers of all ages is speeding, which is particularly risky for young novice drivers who, due to their driving inexperience, have difficulty in identifying and responding appropriately to road hazards. Psychosocial theory can improve our understanding of contributors to speeding, thereby informing countermeasure development and evaluation. This paper reports an application of Akers’ social learning theory (SLT), augmented by Gerrard and Gibbons’ prototype/willingness model (PWM), in addition to personal characteristics of age, gender, car ownership, and psychological traits/states of anxiety, depression, sensation seeking propensity and reward sensitivity, to examine the influences on self-reported speeding of young novice drivers with a Provisional (intermediate) licence in Queensland, Australia.

Method

Young drivers (n = 378) recruited in 2010 for longitudinal research completed two surveys containing the Behaviour of Young Novice Drivers Scale, and reported their attitudes and behaviours as pre-Licence/Learner (Survey 1) and Provisional (Survey 2) drivers and their sociodemographic characteristics.

Results

An Akers’ measurement model was created. Hierarchical multiple regressions revealed that (1) personal characteristics (PC) explained 20.3%; (2) the combination of PC and SLT explained 41.1%; (3) the combination of PC, SLT and PWM explained 53.7% of variance in self-reported speeding. Whilst there appeared to be considerable shared variance, the significant predictors in the final model included gender, car ownership, reward sensitivity, depression, personal attitudes, and Learner speeding.

Conclusions

These results highlight the capacity for psychosocial theory to improve our understanding of speeding by young novice drivers, revealing relationships between previous behaviour, attitudes, psychosocial characteristics and speeding. The findings suggest multi-faceted countermeasures should target the risky behaviour of Learners, and Learner supervisors should be encouraged to monitor their Learners’ driving speed. Novice drivers should be discouraged from developing risky attitudes towards speeding.     

Which visual measures affect change in driving difficulty after first eye cataract surgery?

Objective

To investigate self-reported driving difficulty before and after first eye cataract surgery and determine which visual measures are associated with changes in self-reported driving difficulty after surgery.

Methods

A cohort of 99 older drivers with bilateral cataract were assessed the week before and 12 weeks after first eye cataract surgery. Visual measures including visual acuity, contrast sensitivity, stereopsis and useful field of view were assessed. Self-reported driving difficulty was measured via the Driving Habits Questionnaire. Cognitive status was assessed using the Mini Mental State Examination. Regression analysis was undertaken to determine the association between changes in visual measures and self-reported driving difficulty after first eye cataract surgery.

Results

Overall, self-reported driving difficulty improved after first eye cataract surgery. However, 16% of participants did not improve and driving difficulty worsened in 11% following surgery. Improvement in driving difficulty score after first eye cataract surgery was associated with improved contrast sensitivity in the operated eye (p < 0.001), new glasses after surgery (p < 0.001), and fewer chronic health conditions (p = 0.016).

Conclusion

Contrast sensitivity rather than visual acuity was a significant factor affecting change in self-reported driving difficulty after first eye cataract surgery for bilateral patients. This has implications for driver licensing authorities worldwide that rely heavily on visual acuity as a measure of visual fitness to drive.     

Experimental examination of the effects of televised motor vehicle commercials on risk-positive attitudes,emotions and risky driving inclinations

Purpose

This study examined the short-term effects of risky driving motor vehicle television commercials on risk-positive attitudes, emotions and risky driving inclinations in video-simulated critical road traffic situations among males and females, within an experimental design.

Method

Participants were randomly assigned to one of three televised commercial advertising conditions embedded in a television show: a risky driving motor vehicle commercial condition, a non-risky driving motor vehicle commercial condition and a control non-motor vehicle commercial condition. Participants subsequently completed the Implicit Attitude Test (IAT) to measure risk-positive attitudes, Driver Thrill Seeking Scale (DTSS) to measure risk-positive emotions and the Vienna Risk-Taking Test – Traffic (WRBTV) to measure risky driving inclinations.

Results

ANOVA analyses indicated that type of commercial participants watched did not affect their performance on the IAT, DTSS or WRBTV. However, a main effect of heightened risk-positive emotions and risky driving inclinations was found for males.

Discussion

Despite public and governmental concern that risky driving motor vehicle commercials may increase the likelihood that people exposed to these commercials engage in risky driving, this experimental study found no immediate effect of brief exposure to a risky driving motor vehicle commercial on risk-positive attitudes, emotions or risky driving inclinations. Subsequent research should examine the effects of cumulative exposure to risky driving motor vehicle television commercials and print advertisements.     

The prevalence and nature of stopped on-the-road driving tests and the relationship with objective performance impairment

Introduction and objectives

The on-the-road driving test in normal traffic is applied to examine the impact of drugs on driving performance. Although participants are accompanied by a licensed driving instructor, under Dutch law, the driver is primarily responsible for safe driving and is not permitted to continue driving when it is judged that the drug compromises safety. This review examined the prevalence and nature of stopped driving tests, and the relationship with Standard Deviation of Lateral Position (SDLP), i.e. the “weaving of the car”.

Materials and methods

A literature search was conducted to gather all publications on clinical trials that applied the on-the-road driving test, examining the effects of Central Nervous System (CNS)-drugs such as anxiolytics, antidepressants, antihistamines, analgesics, and hypnotics.

Results

47 papers reported on 50 Dutch clinical trials in which 1059 subjects participated (903 healthy volunteers and 156 patients). A total of 7232 driving tests were performed; 5050 after drug treatment and 2042 after placebo. 3.1% of all driving tests were terminated before completion: 4.1% after drug treatment, and 0.7% after placebo. The decision to stop a driving test was 3–4 times more often made by the driving instructor than the subject. The most common reasons for stopping were the driver feeling tired or sleepy, or the driving instructor noticing signs of drowsiness and performance impairment. Although SDLP values of stopped driving tests are sometimes high, there is no clear relationship between SDLP (changes from placebo) and the decision to stop a driving test. Based on 8 studies that reported exact data, 39.6% of stopped drivers had a lower and 60.4% had a higher SDLP than 35 cm, i.e. the cut-off point of safe driving. This confirms that perception of the driver as well as judgment by the instructor of driving to be ‘unsafe’ differs between individuals.

Conclusion

Driving tests are sometimes stopped after drug treatment or placebo. The decision to stop driving is not a good correlate of objective performance.     

Hostility,driving anger,and dangerous driving: The emerging role of hemispheric preference

Background

Various studies have implicated psychosocial variables (e.g., hostility) in risk of dangerous driving and traffic accidents. However, whether these variables are related to more basic neurobiological factors, and whether such associations have implications for the modification of psychosocial risk factors in the context of driving, have not been examined in depth. This study examined the relationship between hemispheric preference (HP), hostility and self-reported dangerous driving, and the ability to affect driving anger via hemisphere activating cognitive exercises (HACE).

Methods

In Study 1, 254 Turkish students completed questionnaires of hostility, HP and driving behavior. In Study 2, we conducted a “proof of concept” experimental study, and tested effects of left, right and neutral HACE on driving anger, by exposing N = 650 Turkish students to written scenarios including either logical (left hemisphere), visuo-spatial (right hemisphere) or “mild doses” of both types of contents (control).

Results

In Study 1, left-HP was associated with higher hostility and with more dangerous driving, and hostility mediated the relationship between L-HP and reported driving behavior. In Study 2, only right-HACE led to immediate significant reductions in self-reported driving anger.

Conclusions

Left-HP is related to hostility and to dangerous driving, and it may be possible to partly reduce driving anger by right-HACE. Future studies must replicate these findings with objective measures, more enduring interventions and longer follow-ups.     

Road safety impact of Ontario street racing and stunt driving law

Objective

The purpose of this study was to conduct a process and outcome evaluation of the deterrent impact of Ontario's street racing and stunt driving legislation which came into effect on September 30, 2007, on collision casualties defined as injuries and fatalities. It was hypothesized that because males, especially young ones, are much more likely to engage in speeding, street racing and stunt driving, the new law would have more impact in reducing speeding-related collision casualties in males when compared to females.

Methods

Interrupted time series analysis with ARIMA modelling was applied to the monthly speeding-related collision casualties in Ontario for the period of January 1, 2002 to December 31, 2010, separately for young male drivers 16–25 years of age (primary intervention group), mature male drivers 26–65 years of age (secondary intervention group), young female drivers 16–25 years of age (primary comparison group) and mature female drivers 26–65 years of age (secondary comparison group). A covariate adjustment using non-speeding casualties was included.

Results

A significant intervention effect was found for young male drivers with, on average, 58 fewer collision casualties per month, but not for mature male drivers, when non-speeding casualties were controlled for. No corresponding effect was observed in either comparison (females) group.

Conclusion

These findings indicate a reduction in speeding-related casualties among young males of 58 fewer casualties per month subsequent to the introduction of Ontario's street racing and stunt driving legislation and suggest the presence of a general deterrent effect.     

The effects of driver identity on driving safety in a retrospective feedback system

Background

Retrospective feedback that provides detailed information on a driver's performance in critical driving situations at the end of a trip enhances his/her driving behaviors and safe driving habits. Although this has been demonstrated by a previous study, retrospective feedback can be further improved and applied to non-critical driving situations, which is needed for transportation safety.

Objectives

To propose a new retrospective feedback system that uses driver identity (i.e., a driver's name) and to experimentally study its effects on measures of driving performance and safety in a driving simulator.

Method

We conducted a behavioral experimental study with 30 participants. “Feedback type” was a between-subject variable with three conditions: no feedback (control group), feedback without driver identity, and feedback with driver identity. We measured multiple aspects of participants’ driving behavior. To control for potential confounds, factors that were significantly correlated with driving behavior (e.g., age and driving experience) were all entered as covariates into a multivariate analysis of variance. To examine the effects of speeding on collision severity in driving simulation studies, we also developed a new index – momentum of potential collision – with a set of equations.

Results

Subjects who used a feedback system with driver identity had the fewest speeding violations and central-line crossings, spent the least amount of time speeding and crossing the central line, had the lowest speeding and central-line crossing magnitude, ran the fewest red lights, and had the smallest momentum of potential collision compared to the groups with feedback without driver identity and without feedback (control group).

Conclusions

The new retrospective feedback system with driver identity has the potential to enhance a person's driving safety (e.g., speeding, central-line crossing, momentum of potential collision), which is an indication of the valence of one's name in a feedback system design.     

Effects of mobile Internet use on college student pedestrian injury risk

Background

College-age individuals have the highest incidence of pedestrian injuries of any age cohort. One factor that might contribute to elevated pedestrian injuries among this age group is injuries incurred while crossing streets distracted by mobile devices.

Objectives

Examine whether young adult pedestrian safety is compromised while crossing a virtual pedestrian street while distracted using the Internet on a mobile “smartphone.”

Method

A within-subjects design was implemented with 92 young adults. Participants crossed a virtual pedestrian street 20 times, half the time while undistracted and half while completing an email-driven “scavenger hunt” to answer mundane questions using mobile Internet on their cell phones. Six measures of pedestrian behavior were assessed during crossings. Participants also reported typical patterns of street crossing and mobile Internet use.

Results

Participants reported using mobile Internet with great frequency in daily life, including while walking across streets. In the virtual street environment, pedestrian behavior was greatly altered and generally more risky when participants were distracted by Internet use. While distracted, participants waited longer to cross the street (F = 42.37), missed more safe opportunities to cross (F = 42.63), took longer to initiate crossing when a safe gap was available (F = 53.03), looked left and right less often (F = 124.68), spent more time looking away from the road (F = 1959.78), and were more likely to be hit or almost hit by an oncoming vehicle (F = 29.54; all ps < 0.01). Results were retained after controlling for randomized order; participant gender, age, and ethnicity; and both pedestrian habits and mobile Internet experience.

Conclusion

Pedestrian behavior was influenced, and generally considerably riskier, when participants were simultaneously using mobile Internet and crossing the street than when crossing the street with no distraction. This finding reinforces the need for increased awareness concerning the risks of distracted pedestrian behavior.     

Jerky driving--An indicator of accident proneness?

This study uses continuously logged driving data from 166 private cars to derive the level of jerks caused by the drivers during everyday driving. The number of critical jerks found in the data is analysed and compared with the self-reported accident involvement of the drivers. The results show that the expected number of accidents for a driver increases with the number of critical jerks caused by the driver. Jerk analyses make it possible to identify safety critical driving behaviour or “accident prone” drivers. They also facilitate the development of safety measures such as active safety systems or advanced driver assistance systems, ADAS, which could be adapted for specific groups of drivers or specific risky driving behaviour.     

The impact of childhood symptoms of conduct disorder on driver aggression in adulthood

Background

Despite limited empirical investigation, existing scientific literature suggests that individuals with a history or current diagnosis of conduct disorder (CD) may be more likely to demonstrate reckless and aggressive driving. Much of the limited research in this field examines the impact of childhood CD on driver behaviour and collision risk in young adults. Few if any, studies assess the impact of this disorder on driver behaviour beyond age 21 years. The current research is a population-based study of the impact of CD symptoms during childhood on the risk of engaging in driver aggression during adulthood.

Methods

Data are based on telephone interviews with 5230 respondents who reported having driven in the past year. Data are derived from the 2011–2013 cycles of the CAMH Monitor, an ongoing cross-sectional survey of adults in Ontario, Canada aged 18 years and older. A binary logistic regression analysis of self-reported driver aggression in the previous 12 months was conducted, consisting of measures of demographic characteristics, driving exposure, problem substance use, alcohol- and drug-impaired driving, symptoms of attention deficit hyperactivity disorder, and childhood (before age 15) symptoms of CD.

Results

When entered with demographic characteristics, driving exposure, and other potential confounders, childhood symptoms of CD increased the odds of reporting driver aggression more than two-fold (adjusted OR = 2.12). Exploratory analyses of the interaction between childhood symptoms of CD and age was not a significant predictor of driver aggression.

Conclusions

Results suggest that symptoms of CD during childhood are associated with significantly increased odds of self-reported driver aggression during adulthood. Limitations and future directions of the research are discussed.     

Forgivingness,anger, and hostility in aggressive driving

This study was aimed at investigating the relationship between trait forgivingness, general anger, hostility, driving anger, and self-reported aggressive driving committed by the driver him/herself (“self” scale) and perceiving him/herself as an object of other drivers’ aggressive acts (“other” scale). The Slovak version of questionnaires was administrated to a sample of 612 Slovak and Czech drivers. First, the factor structure of the Driver Anger Indicators Scale (DAIS) was investigated. Factor analyses of the self and other parts of the DAIS resulted in two factors, which were named as aggressive warnings and hostile aggression and revenge. Next, the results showed that from all dependent variables (scales of the DAIS), self-reported aggressive warnings (self) on the road were predicted best by chosen person-related factors. The path model for aggressive warnings (self) suggested that trait forgivingness and general anger were fully mediated by driving anger whereas hostility proved to be a unique predictor of aggressive behavior in traffic. Driving anger was found to be the best predictor of perceptions that other drivers behave aggressively.     

Young novice driver subtypes: Relationship to driving violations, errors and lapses

The present study aimed to identify, in a large Italian sample of young, novice drivers, specific subtypes of drivers on the basis of combinations of self-reported personality traits (i.e., driving anger, anxiety, angry hostility, excitement-seeking, altruism, normlessness and driving locus of control) and to evaluate their high-risk driving behaviors not only in terms of traffic rule violations and risk-taking behaviors, but also in terms of driving errors and lapses as measured by the Manchester Driver Behavior Questionnaire. Participants were 1008 high school students between the ages of 18 and 23 years, with valid driver's licenses. On the basis of a cluster analysis of the personality variables, three easily interpretable driver subgroups were identified (risky drivers, worried drivers and careful drivers) that differed on self-reported accident involvement, attitudes toward traffic safety and risk perception, as well as on driving violations, errors, and lapses. The inclusion of internal and external driving locus of control, variables not previously considered in similar cluster studies, provided a relevant contribution to the final cluster solution. Further, the use of the Driving Behavior Questionnaire permitted the differentiation between deliberate deviations from safe driving practices and mistakes due to misjudgments or lapses in attention. This distinction was critical for understanding the behavior of each of the three identified subgroups of drivers, and for planning interventions to promote safe driving.     

Young novice drivers and the risky behaviours of parents and friends during the Provisional (intermediate) licence phase: A brief report

Purpose

While there is research indicating that many factors influence the young novice driver's increased risk of road crash injury during the earliest stages of their independent driving, there is a need to further understand the relationship between the perceived risky driving behaviour of parents and friends and the risky behaviour of drivers with a Provisional (intermediate) licence.

Method

As part of a larger research project, 378 drivers aged 17–25 years (M = 18.22, SD = 1.59, 113 males) with a Provisional licence completed an online survey exploring the perceived riskiness of their parents’ and friends’ driving, and the extent to which they pattern (i.e. base) their driving behaviour on the driving of their parents and friends.

Results

Young drivers who reported patterning their driving on their friends, and who reported they perceived their friends to be risky drivers, reported more risky driving. The risky driving behaviour of young male drivers was associated with the perceived riskiness of their fathers’ driving, whilst for female drivers the perceived riskiness of their mothers’ driving approached significance.

Conclusions

The development and application of countermeasures targeting the risky behaviour of same-sex parents appears warranted by the robust research findings. In addition, countermeasures need to encourage young people in general to be non-risky drivers; targeting the negative influence of risky peer groups specifically. Social norms interventions may minimise the influence of potentially-overestimated riskiness.     

Does gender moderate the relationship between driver aggression and its risk factors?

Aim

The current study assessed gender as a potential moderator of the relationship between self-reported driver aggression and various demographic variables, general and driving-related risk factors.

Methods

Using data from a general-population telephone survey conducted from July 2002 through June 2005, two approaches to binary logistic regression were adopted. Based on the full dataset (n = 6259), the initial analysis was a hierarchical-entry regression examining self-reported driver aggression in the last 12 months. All demographic variables (i.e., gender, age, income, education, marital status), general risk factors (i.e., psychological distress, binge drinking, cannabis use), and driving-related risk factors (i.e., driving exposure, stressful driving, exposure to busy roads, driving after drinking, driving after cannabis use) were entered in the first block, and all two-way interactions with gender were entered stepwise in the second block. The subsequent analysis involved dividing the sample by gender and conducting logistic regressions with main effects only for males (n = 2921) and females (n = 3338) separately.

Results

Although the prevalence of driver aggression in the current sample was slightly higher among males (38.5%) than females (32.9%), the difference was small, and gender did not enter as a significant predictor of driver aggression in the overall logistic regression. In that analysis, difficulty with social functioning and being older were associated with a reduced risk of driver aggression. Marital status and education were unrelated to aggression, and all other variables were associated with an increased risk of aggression. Gender was found to moderate the relationships between driver aggression and only three variables: income, psychological distress, and driving exposure. Separate analyses on the male and female sub-samples also found differences in the predictive value of income and driving exposure; however, the difference for psychological distress could not be detected using this separate regression approach. The secondary analysis also identified slight differences in the predictive value of four of the risk factors, where the odds ratios for both males and females were in the same direction but only one of the two was statistically significant.

Conclusions

The results demonstrate the importance of conducting the gender analysis using both regression approaches. With few exceptions, factors that were predictive of driver aggression were generally the same for both male and female drivers.     

Young driver crash rates by licensing age,driving experience,and license phase

Background

Few studies have concurrently assessed the influence of age and experience on young driver crashes, in particular in the post-Graduated Driver Licensing (GDL) era. Further, little attention is given to the transition from intermediate to full licensure. We examined the independent and joint contributions of licensing age, driving experience, and GDL license phase on crash rates among the population of young New Jersey (NJ) drivers.

Methods

From a unique linked database containing licensing and crash data, we selected all drivers who obtained their NJ intermediate license at 17–20 years old from 2006–2009 (n = 410,230). We determined the exact age at which each driver obtained an intermediate and full license and created distinct, fixed cohorts of drivers based on their age at intermediate licensure. For each cohort, we calculated and graphed observed monthly crash rates over the first 24 months of licensure. Further, we examined crash rates by age at licensure, driving experience (i.e., time since licensure), and license phase.

Results

First-month crash rates were higher among the youngest drivers (licensed at 17y0m). Drivers who were licensed later experienced a reduced “steepness” in the slope of their crash rates in the critical initial months of driving, but there did not appear to be any incremental benefit of later licensure once drivers had six months of driving experience. Further, at each age, those with more driving experience had lower crash rates; however, the benefit of increased experience was greatest for the substantial proportion of teens licensed immediately after becoming eligible (at 17y0m). Finally, independent of age and experience, teen drivers’ crash risk increased substantially at the point of transition to a full license, while drivers of a similar age who remained in the intermediate phase continued to experience a decline in crash rates.

Conclusion

Age and driving experience interact to influence crash rates. Further, independent of these two factors, there is an abrupt increase in crash risk at the point of transition from intermediate to full licensure. Future studies should investigate whether this increase is accounted for by a change in driving exposure, driving behaviors, and/or other factors.