Novice drivers' exposure to known risk factors during the first 18 months of licensure: the effect of vehicle ownership

Young drivers' early access to their own car and crash risk into early adulthood: Findings from the DRIVE study

INTRODUCTION

Car ownership at early licensure for young drivers has been identified as a crash risk factor, but for how long this risk persists is unknown. This study examined crash hazard rates between young drivers with their own vehicle and those who shared a family vehicle at early licensure over 13 years.

METHODS

The DRIVE study, a 2003/04 survey of 20,806 young novice drivers in New South Wales, Australia was used to link to police crash, hospital and death records up to 2016. The first police-reported crash and crash resulting in hospitalisation/death was modelled via flexible parametric survival analysis by type of vehicle access at baseline (own vs. shared family vehicle).

RESULTS

After adjusting for covariates, drivers with their own vehicle at early licensure had an almost 30 % increased hazard rate for any crash after one year (95 % CI:1.16-1.42) compared with those who only had access to a family car and this attenuated but remained significantly higher until year 7 (HR: 1.1, 95 % CI: >1.00-1.20). For crashes resulting in hospitalisation or death, an almost 15-times higher hazard (95 % CI: 1.40-158.17) was observed at the start of follow up, remaining 50 % to year 3 (95 % CI:1.01-2.18).

CONCLUSIONS

Parents and young drivers should be aware of the increased risks involved in car ownership at early licensure. Development of poorer driving habits has been associated with less parental monitoring at this time. Graduated Driving Licensing educators, researchers and stakeholders should seek to address this and to identify improved safety management options.

Characteristics of Single Vehicle Crashes with a Teen Driver in South Carolina, 2005-2008

OBJECTIVE

Teens' crash risk is highest in the first years of independent driving. Circumstances surrounding fatal crashes have been widely documented, but less is known about factors related to nonfatal teen driver crashes. This study describes single vehicle nonfatal crashes involving the youngest teen drivers (15-17 years), compares these crashes to single vehicle nonfatal crashes among adult drivers (35-44 years) and examines factors related to nonfatal injury producing crashes for teen drivers.

METHODS

Police crash data linked to hospital inpatient and emergency department data for 2005-2008 from the South Carolina Crash Outcomes Data Evaluation System (CODES) were analyzed. Nonfatal, single vehicle crashes involving passenger vehicles occurring on public roadways for teen (15-17 years) drivers were compared with those for adult (35-44 years) drivers on temporal patterns and crash risk factors per licensed driver and per vehicle miles traveled. Vehicle miles traveled by age group was estimated using data from the 2009 National Household Travel Survey. Multivariable log-linear regression analysis was conducted for teen driver crashes to determine which characteristics were related to crashes resulting in a minor/moderate injury or serious injury to at least one vehicle occupant.

RESULTS

Compared with adult drivers, teen drivers in South Carolina had 2.5 times the single vehicle nonfatal crash rate per licensed driver and 11 times the rate per vehicle mile traveled. Teen drivers were nearly twice as likely to be speeding at the time of the crash compared with adult drivers. Teen driver crashes per licensed driver were highest during the afternoon hours of 3:00-5:59 pm and crashes per mile driven were highest during the nighttime hours of 9:00-11:59 pm. In 66% of the teen driver crashes, the driver was the only occupant. Crashes were twice as likely to result in serious injury when teen passengers were present than when the teen driver was alone. When teen drivers crashed while transporting teen passengers, the passengers were >5 times more likely to all be restrained if the teen driver was restrained. Crashes in which the teen driver was unrestrained were 80% more likely to result in minor/moderate injury and 6 times more likely to result in serious injury compared with crashes in which the teen driver was restrained.

CONCLUSIONS

Despite the reductions in teen driver crashes associated with Graduated Driver Licensing (GDL), South Carolina's teen driver crash rates remain substantially higher than those for adult drivers. Established risk factors for fatal teen driver crashes, including restraint nonuse, transporting teen passengers, and speeding also increase the risk of nonfatal injury in single vehicle crashes. As South Carolina examines strategies to further reduce teen driver crashes and associated injuries, the state could consider updating its GDL passenger restriction to either none or one passenger <21years and dropping the passenger restriction exemption for trips to and from school. Surveillance systems such as CODES that link crash data with health outcome data provide needed information to more fully understand the circumstances and consequences of teen driver nonfatal crashes and evaluate the effectiveness of strategies to improve teen driver safety.

Vehicle ownership and other predictors of teenagers risky driving behavior: Evidence from a naturalistic driving study

OBJECTIVE

Risky driving behavior may contribute to the high crash risk among teenage drivers. The current naturalistic driving study assessed predictors for teenagers' kinematic risky driving (KRD) behavior and the interdependencies between them.

METHOD

The private vehicles of 81 novice teenage drivers were equipped with data acquisition system that recorded driving kinematics, miles driven, and video recordings of the driver, passengers and the driving environment. Psychosocial measures were collected using questionnaires administered at licensure. Poisson regression analyses and model selection were used to assess factors associated with teens' risky driving behavior and the interactions between them.

RESULTS

Driving own vs shared vehicle, driving during the day vs at night, and driving alone vs with passengers were significantly associated with higher KRD rates (Incidence rate ratios (IRRs) of 1.60, 1.41, and 1.28, respectively). Teenagers reporting higher vs lower levels of parental trust had significantly lower KRD rates (IRR = 0.58). KRD rates were 88% higher among teenagers driving with a passenger in their own vehicle compared to teenagers driving with a passenger in a shared vehicle. Similarly, KRD rates during the day were 74% higher among teenagers driving their own vehicle compared to those driving a shared vehicle.

CONCLUSIONS

Novice teenagers' risky driving behavior varied according to driver attributes and contextual aspects of the driving environment. As such, examining teenagers' risky driving behavior should take into account multiple contributing factors and their interactions. The variability in risky driving according to the driving context can inform the development of targeted interventions to reduce the crash risk of novice teenage drivers.

Young Driver Compliance With Graduated Driver Licensing Restrictions Before and After Implementation of a Decal Provision

PURPOSE

In May 2010, New Jersey implemented the first-in-the-nation decal provision to increase intermediate drivers' compliance with Graduated Driver Licensing restrictions and ultimately reduce young driver crashes. We previously found that the provision was associated with a 9.5% decline in crash rates. This study evaluates whether the decal provision was associated with an increase in compliance with passenger and nighttime restrictions.

METHODS

We analyzed New Jersey driver licensing and crash data from 2008 through 2012. We used the quasi-induced exposure method to estimate prevalence of noncompliance among 20,593 nonresponsible 17- to 20-year-old intermediate drivers involved in crashes. Multivariate log-binomial regression models compared the monthly prevalence of noncompliance with restrictions pre and post implementation, adjusted for age, sex, season, and area income and population density. Analyses were conducted in 2016-2017.

RESULTS

Overall estimated noncompliance with the nighttime restriction was 1.75% before and 1.71% after the decal provision (p = .83). Noncompliance with the passenger restriction was 8.68% before and 8.31% after (p = .35). Introduction of the decal provision was not associated with a change in noncompliance rates.

CONCLUSIONS

Compliance rates among New Jersey intermediate drivers were high both before and after the decal provision. Findings do not suggest that the decline in crash rates following implementation was because of increased compliance with nighttime or passenger driving restrictions. Additional research is needed to understand mechanisms by which decal provisions may reduce young driver crashes.

Young drivers and their cars: Safe and sound or the perfect storm?

Consistent with the experiences in high-income countries, young drivers remain overrepresented in road trauma statistics in low- and middle-income countries. This article pursues the emerging interest of approaching the young driver problem from a systems thinking perspective in order to design and deliver robust countermeasures. Specifically, the focus of this paper is the cars driven by young drivers. The study of vehicles' characteristics and their interaction with driving behaviour is, more often than not, considered a minor concern when developing countermeasures in young drivers' safety not only in developed nations, but especially in developing nations. Participants completed an online survey containing the 44-item Behaviour of Young Novice Drivers Scale Spanish version (BYNDS-Sp), in addition to providing information regarding their vehicle, any crash involvement, and driving offences. Based on the vehicle model information, the assessment of vehicle safety was conducted for three safety programs (ANCAP, Latin NCAP, U.S. NCAP). Young drivers in Colombia reported a breadth of risky driving behaviours worth targeting in broader interventions. For example, interventions can target speeding, particularly as three quarters of the participants drove small-medium cars associated with poorer road safety outcomes. Moreover, risky driving exposure was highly prevalent amongst the young driver participants, demonstrating the need for them to be driving the safest vehicles possible. It is noteworthy that few cars were able to be assessed by the Latin NCAP (with half of the cars rated having only 0-2 star ratings), and that there was considerable discrepancy between ANCAP, U.S. NCAP, and Latin NCAP ratings. The need for system-wide strategies to increase young driver road safety-such as improved vehicle safety-is vital to improve road safety outcomes in jurisdictions such as Colombia. Such improvements may also require systemic changes such as enhanced vehicle safety rating scales and investigation of the nature of vehicles sold in developing nations, particularly as these vehicles typically contain fewer safety features than their counterparts sold in developed nations.

Teens' distracted driving behavior: Prevalence and predictors

INTRODUCTION

Teen drivers' over-involvement in crashes has been attributed to a variety of factors, including distracted driving. With the rapid development of in-vehicle systems and portable electronic devices, the burden associated with distracted driving is expected to increase. The current study identifies predictors of secondary task engagement among teenage drivers and provides basis for interventions to reduce distracted driving behavior. We described the prevalence of secondary tasks by type and driving conditions and evaluated the associations between the prevalence of secondary task engagement, driving conditions, and selected psychosocial factors.

METHODS

The private vehicles of 83 newly-licensed teenage drivers were equipped with Data Acquisition Systems (DAS), which documented driving performance measures, including secondary task engagement and driving environment characteristics. Surveys administered at licensure provided psychosocial measures.

RESULTS

Overall, teens engaged in a potentially distracting secondary task in 58% of sampled road clips. The most prevalent types of secondary tasks were interaction with a passenger, talking/singing (no passenger), external distraction, and texting/dialing the cell phone. Secondary task engagement was more prevalent among those with primary vehicle access and when driving alone. Social norms, friends' risky driving behaviors, and parental limitations were significantly associated with secondary task prevalence. In contrast, environmental attributes, including lighting and road surface conditions, were not associated with teens' engagement in secondary tasks.

CONCLUSIONS

Our findings indicated that teens engaged in secondary tasks frequently and poorly regulate their driving behavior relative to environmental conditions. Practical applications: Peer and parent influences on secondary task engagement provide valuable objectives for countermeasures to reduce distracted driving among teenage drivers.

Provisional drivers' perceptions of the impact of displaying P plates

OBJECTIVE

P plates (or decals) identify a driver's license status to other road users. They are a compulsory part of the graduated driver licensing system in Queensland, Australia, for drivers on a P1 (provisional 1) or P2 (provisional 2) license. This study explored the perceptions of young drivers regarding the display of P plates (decals) in Queensland, Australia.

METHODS

In this study, 226 young drivers with a provisional (intermediate/restricted) license completed a 30-min online survey between October 2013 and June 2014. t Tests were used to compare the opinions of people who displayed their plates nearly always with those who displayed them less frequently.

RESULTS

Participants approved of the requirement to display P plates with 69% of those on a P1 license and 79% on a P2 license supporting the condition to display P1 (red) plates. Participants on a P1 license (62%) and a P2 license (68%) also approved the requirement to display P2 (green) plates. However, young drivers also perceived that the display of P plates (measured from 1 = never to 5 = nearly all the time) enabled newly licensed drivers to be targeted by police and other drivers (those who do not always display P plates: M = 3.72, SD = 0.94; those who nearly always display P plates: M = 3.43, SD = 1.09).

CONCLUSIONS

The study findings suggest that participants who nearly always display their P plates are more likely to report that having to display their plates resulted in them driving more carefully.

Comparison of older and younger novice driver crash rates: Informing the need for extended Graduated Driver Licensing restrictions

BACKGROUND

Few previous studies have directly compared crash rates of older and younger novice drivers. To inform discussion about whether Graduated Driver Licensing (GDL) policies that are applied in the US for younger novice drivers should be applied to older novice drivers, we conducted a longitudinal study to examine overall, nighttime, and multiple passenger crash rates over the initial four years of licensure differ for novice drivers licensed at different ages.

METHODS

Using data from the New Jersey Traffic Safety Outcomes (NJ-TSO) data warehouse, we selected all NJ drivers who obtained their initial intermediate driver's license from 2006 through 2014 and had at least one month of follow-up from the date of licensure to study end or death (n=1,034,835). Novice drivers were grouped based on age at licensure: age 17; 18-20; 21-24; and 25 or older. We estimated monthly rates for overall crashes (per 10,000 licensed drivers) as well as: late night crashes (11:01 p.m.-4:59 a.m.); early night crashes (9:00 p.m.-11:00 p.m.); and multiple passenger crashes (two or more passengers). Average monthly rates were calculated for specific relevant time periods and Poisson regression models were used to compare rates: (1) between novice driver groups with the same time since licensure; (2) over the first 48 months of licensure within each novice driver group; and (3) between same-aged 21-year-old drivers with varying lengths of licensure.

RESULTS

Although initial (three months post-licensure) overall crash rates of novice NJ drivers age 21 and older were higher than rates of same-aged experienced drivers, they were substantially lower than initial rates for 17- to 20-year-old novice drivers, who are licensed under GDL policies. Moreover, older novice drivers experience much less steep crash reductions over the first year of licensure than younger novice drivers. Nighttime crash rates among the 21- to 24-year old and aged 25 and older novice driver groups were stable over the first year of licensure. For novice drivers under age 21, early night crash rates declined rapidly over the course of licensure, while changes in late night crashes were much smaller. First-year multiple passenger crash rates were highest for drivers licensed at age 18-20, and novice driver groups experienced varying amounts of reduction in multiple passenger crashes over time.

CONCLUSIONS

Study findings support NJ's current GDL policies for 17- to 20-year-old novice drivers and the potential for added benefits from beginning the nighttime restriction at 9:00 p.m. Conversely, there was a lack of compelling evidence for additional policies for drivers licensed at age 21-24 and no evidence to indicate a need for additional GDL policies for NJ novices aged 25 years and older.

Factors Influencing Learner Permit Duration

An increasing number of countries are requiring an extended learner permit prior to independent driving. The question of when drivers begin the learner permit period, and how long they hold the permit before advancing to independent licensure has received little research attention. Licensure timing is likely to be related to "push" and "pull" factors which may encourage or inhibit the process. To examine this question, we recruited a sample of 90 novice drivers (49 females and 41 males, average age of 15.6 years) soon after they obtained a learner permit and instrumented their vehicles to collect a range of driving data. Participants completed a series of surveys at recruitment related to factors that may influence licensure timing. Two distinct findings emerged from the time-to-event analysis that tested these push and pull factors in relation to licensure timing. The first can be conceptualized as teens' motivation to drive (push), reflected in a younger age when obtaining a learner permit and extensive pre-permit driving experience. The second finding was teens' perceptions of their parents' knowledge of their activities (pull); a proxy for a parents' attentiveness to their teens' lives. Teens who reported higher levels of their parents' knowledge of their activities took longer to advance to independent driving. These findings suggest time-to-licensure may be related to teens' internal motivation to drive, and the ability of parents to facilitate or impede early licensure.

Estimating young novice drivers' compliance with graduated driver licensing restrictions: A novel approach

OBJECTIVES

Current methods of estimating compliance with graduated driver licensing (GDL) restrictions among young drivers with intermediate driver's licenses-which include surveys, direct observations, and naturalistic studies-cannot sufficiently answer many critical foundational questions: What is the extent of noncompliance among the population of young intermediate drivers? How does compliance change over the course of licensure? How does compliance differ by driver subgroup and in certain driving environments? This article proposes an alternative and complementary approach to estimating population-level compliance with GDL nighttime and passenger restrictions via application of the quasi-induced exposure (QIE) method.

METHODS

The article summarizes the main limitations of previous methods employed to estimate compliance. It then introduces the proposed method of borrowing the fundamental assumption of the QIE method-that young intermediate drivers who are nonresponsible in clean (i.e., one and only one responsible driver) multivehicle crashes are reasonably representative of young intermediate drivers on the road-to estimate population-based compliance. I describe formative work that has been done to ensure this method can be validly applied among young intermediate drivers and provide a practical application of this method: an estimate of compliance with New Jersey's passenger restrictions among 8,006 nonresponsible 17- to 20-year-old intermediate drivers involved in clean 2-vehicle crashes from July 2010 through June 2012.

RESULTS

Over the study period, an estimated 8.4% (95% confidence interval, 7.8%, 9.0%) of intermediate drivers' trips were not in compliance with New Jersey's GDL passenger restriction. These findings were remarkably similar to previous estimates from more resource-intensive naturalistic studies (Goodwin et al. 2006 ; Klauer et al. 2011 ).

CONCLUSION

Studies can practically apply proposed methods to estimate population-level compliance with GDL passenger and night restrictions; examine how compliance varies by relevant driver, vehicle, and environmental factors; and evaluate the implementation of a GDL provision or other intervention aimed at increasing compliance with these restrictions. Important considerations and potential limitations and challenges are discussed.

Compliance With and Enforcement of Graduated Driver Licensing Restrictions

INTRODUCTION

Graduated Driver Licensing (GDL) is the most effective strategy to reduce the burden of young driver crashes, but the extent to which young intermediate (newly licensed) drivers comply with, and police enforce, important GDL passenger and night-time restrictions is largely unknown. Population-level rates of intermediate drivers' compliance were estimated as well as police enforcement among crash-involved drivers who were noncompliant.

METHODS

New Jersey's statewide driver licensing and crash databases were individually linked. The quasi-induced exposure method's fundamental assumption-that nonresponsible young intermediate drivers in clean (i.e., only one responsible driver) multivehicle crashes are reasonably representative of young intermediate drivers on the road-was borrowed. Incidence was then estimated among the 9,250 nonresponsible intermediate drivers who were involved in clean multivehicle crashes from July 2010 through June 2012. The proportion of crash-involved noncompliant intermediate drivers who were issued a GDL citation, by crash responsibility, was calculated. Data were collected in 2013 and analyzed in 2015.

RESULTS

Overall, 8.3% (95% CI=7.8%, 8.9%) of intermediate drivers' trips were noncompliant with New Jersey's passenger restriction and 3.1% (95% CI=2.8%, 3.5%) with its night-time restriction; compliance was significantly lower among those residing in low-income and urban areas, among male drivers, on weekends, and in summer months. The proportion of crash-involved noncompliant intermediate drivers who were issued a GDL citation was low (nonresponsible drivers, 10.3%; responsible drivers, 19.0%).

CONCLUSIONS

The vast majority of intermediate driver trips are in compliance with GDL restrictions. Outreach activities should consider focusing on higher-risk situations and groups with higher noncompliance rates.

Distracted Driving in Teens With and Without Attention-Deficit/Hyperactivity Disorder

OBJECTIVE

This study is among the first to examine the effect of talking on a cell phone or text messaging while driving in teens with and without attention deficit/hyperactivity disorder (ADHD).

METHOD

Teens (average age 17years) with a diagnosis of ADHD (N=16) were matched with typically developing controls (N=18). All participants operated a driving simulator while (1) conversing on a cell phone, (2) text messaging, and (3) with no distraction during a baseline condition. Six indicators of driving performance were recorded: (a) time to complete the drive; (b) lane deviations; (c) variability in lane position (i.e., root mean square [RMS]); (d) reaction time; (e) motor vehicle collisions; and, (f) speed fluctuation.

RESULTS

Significantly greater variation in lane position occurred in the texting task compared to no task and the cell phone task. While texting, in particular, teens with ADHD took significantly less time to complete the scenario. No significant main effects of group were found.

CONCLUSIONS

Generally, those with ADHD did not differ in regard to driving performance, when compared to controls, with the exception of one outcome: time to complete scenario. These findings suggest that distracted driving impairs driving performance of teen drivers, regardless of ADHD status. Texting while driving had the greatest negative impact on driving performance, particularly with regard to variability in lane position (i.e., RMS). This study sheds light on key issues regarding injury prevention, with the intent of providing pediatric care providers with the knowledge to inform teen drivers of risks associated with distracted driving which will ultimately result in reduced rates of motor vehicle crashes and concomitant injuries.

Naturalistic teenage driving study: Findings and lessons learned

INTRODUCTION

This paper summarizes the findings on novice teenage driving outcomes (e.g., crashes and risky driving behaviors) from the Naturalistic Teenage Driving Study.

METHOD

Survey and driving data from a data acquisition system (global positioning system, accelerometers, cameras) were collected from 42 newly licensed teenage drivers and their parents during the first 18 months of teenage licensure; stress responsivity was also measured in teenagers.

RESULT

Overall teenage crash and near-crash (CNC) rates declined over time, but were >4 times higher among teenagers than adults. Contributing factors to teenage CNC rates included secondary task engagement (e.g., distraction), kinematic risky driving, low stress responsivity, and risky social norms.

CONCLUSIONS

The data support the contention that the high novice teenage CNC risk is due both to inexperience and risky driving behavior, particularly kinematic risky driving and secondary task engagement.

PRACTICAL APPLICATIONS

Graduated driver licensing policy and other prevention efforts should focus on kinematic risky driving, secondary task engagement, and risky social norms.

The driver, the road, the rules … and the rest? A systems-based approach to young driver road safety

The persistent overrepresentation of young drivers in road crashes is universally recognised. A multitude of factors influencing their behaviour and safety have been identified through methods including crash analyses, simulated and naturalistic driving studies, and self-report measures. Across the globe numerous, diverse, countermeasures have been implemented; the design of the vast majority of these has been informed by a driver-centric approach. An alternative approach gaining popularity in transport safety is the systems approach which considers not only the characteristics of the individual, but also the decisions and actions of other actors within the road transport system, along with the interactions amongst them. This paper argues that for substantial improvements to be made in young driver road safety, what has been learnt from driver-centric research needs to be integrated into a systems approach, thus providing a holistic appraisal of the young driver road safety problem. Only then will more effective opportunities and avenues for intervention be realised.

Non-compliance with graduated driver licensing (GDL) requirements: changes in GDL-related conviction rates over time among 16-17-year-old California drivers

INTRODUCTION

Self-reports by novice teen drivers in California and elsewhere suggest that many violate graduated driver licensing (GDL) nighttime and passenger restrictions, and to a lesser extent, drive on learner permits without being supervised. Is this corroborated by their traffic conviction records?

METHOD

We examined historical aggregated conviction rates for GDL-related violations before and after GDL, and Poisson regressions of conviction rates over time among 16-17-year-old California novices.

RESULTS

During the year before they received their provisional licenses, <1% of 16-year-old novices and <2% of 17-year-old novices were convicted of driving unlicensed or unsupervised on their learner permits. Statewide historical conviction rates for these offenses were not higher after GDL was implemented, despite the longer holding period. Convictions for violating GDL nighttime or passenger restrictions were highest almost immediately after provisional licensure, though only about 3% of 16-year-old novices and 2% of 17-year-old novices were ever convicted of violating either restriction.

DISCUSSION

California 16-17-year-old novice drivers were very rarely convicted of GDL-related violations. The contradictive, large differences between the current findings and self-report surveys are likely due in part to the fact that most self-reports assessed only whether teens had ever violated a GDL-related requirement, which exaggerates prevalence. Our conviction findings are more similar to estimates of non-compliance with GDL-related requirements from naturalistic driving studies that monitor actual driving behavior and take exposure into account, but are lower likely due to issues related to detection, enforcement, and adjudication of violations, as well as limitations of existing naturalistic studies.

Experiences of teen drivers and their advice for the learner license phase

OBJECTIVE

Teen drivers remain at considerable risk of injury and fatality during the earliest years of independent driving. Multistage licensing programs, such as graduated driver licensing (GDL), have been implemented in numerous jurisdictions as a form of exposure control, mandating minimum practice periods and driving restrictions such as night driving and passenger limits. However, the teen driver's experiences of GDL during the learner phase, and the driving and other advice they recommend be shared with all learners, remains unknown at this time.

METHODS

Thirty-seven learner drivers (aged 16-18 years, mean = 16.7, mode = 16; 9 males) from 2 high schools (one private, 3 males; one public) participated in one of 2 (group 1: private school, n = 17) 45-min group discussions.

RESULTS

Two themes emerged: (1) learning to drive and (2) supervision of the learner driver. A wealth of experiences and advice pertaining to the subthemes of supervisor behavior, GDL, road environment, vehicle logistics, and interacting with other road users were shared by learners. Numerous recommendations are made pertaining to each subtheme, such as clear instruction and feedback, tips for negotiating complex infrastructure, and normalizing of outcomes like stalled vehicles when first learning to drive. Furthermore, it appears that current approaches of issuing supporting literature at the commencement of the learner phase are insufficient.

CONCLUSIONS

The wealth of experiences and advice shared by the learner drivers should be considered in refining the content and process of the learner license phase. Moreover, the nonuse of learner resources suggests that alternative mechanisms of engagement and information dissemination need to be explored.

Crash and traffic violation rates before and after licensure for novice California drivers subject to different driver licensing requirements

INTRODUCTION

How do crash and traffic violation rates for novice 16-17-year-old drivers change over the months before and after licensure under a graduated driver licensing (GDL) program relative to those for older novices who are not subject to GDL?

METHOD

Plots and Poisson regression comparing overall rates and subtypes of crashes and traffic violations among California novice drivers ages 16 to 35 years over time before and after unsupervised licensure.

RESULTS

Majorities of 16-year-olds (57%) and 17-year-olds (73%) actually hold their learner permits longer than the required 6 months; majorities (67%-81%) of age 18 or older novices hold their learner permits less than 6 months. Crash rates of novice 16- and 17-year-olds-as well as most other age groups-are highest almost immediately after they are licensed to drive unsupervised, after which their rates decline quickly during their first year of licensure and at a slower rate for the second and third years. Novice 16- and 17-year-olds' traffic violation rates reach their zenith long after their total crash rates peak and decline, whereas violation rates for older novices peak during their first year of licensure. Over 70% of 16- and 17-year-old novices are crash-free for the first 3 years of licensure.

CONCLUSIONS

While novice 16- and 17-year-olds' highest crash rates occur almost immediately after they are licensed, their peak traffic violation rates are delayed until around the time they turn age 18. Both pre-licensure crash rates and post-licensure crash peaks were more pronounced for some older age groups of novices than was the case for 16-17-year-olds.

PRACTICAL APPLICATIONS

Extending learner permit holding periods for 16-17-year-old novices appears consistent with their actual behavior; requiring older novices-particularly those ages 18 to 20-to hold permits for minimum periods may reduce their initial crash rates.

Higher crash and near-crash rates in teenaged drivers with lower cortisol response: an 18-month longitudinal, naturalistic study

IMPORTANCE

Road traffic crashes are one of the leading causes of injury and death among teenagers worldwide. Better understanding of the individual pathways to driving risk may lead to better-targeted intervention in this vulnerable group.

OBJECTIVE

To examine the relationship between cortisol, a neurobiological marker of stress regulation linked to risky behavior, and driving risk.

DESIGN, SETTING, AND PARTICIPANTS

The Naturalistic Teenage Driving Study was designed to continuously monitor the driving behavior of teenagers by instrumenting vehicles with kinematic sensors, cameras, and a global positioning system. During 2006-2008, a community sample of 42 newly licensed 16-year-old volunteer participants in the United States was recruited and driving behavior monitored. It was hypothesized in teenagers that higher cortisol response to stress is associated with (1) lower crash and near-crash (CNC) rates during their first 18 months of licensure and (2) faster reduction in CNC rates over time.

MAIN OUTCOMES AND MEASURES

Participants' cortisol response during a stress-inducing task was assessed at baseline, followed by measurement of their involvement in CNCs and driving exposure during their first 18 months of licensure. Mixed-effect Poisson longitudinal regression models were used to examine the association between baseline cortisol response and CNC rates during the follow-up period.

RESULTS

Participants with a higher baseline cortisol response had lower CNC rates during the follow-up period (exponential of the regression coefficient, 0.93; 95% CI, 0.88-0.98) and faster decrease in CNC rates over time (exponential of the regression coefficient, 0.98; 95%, CI, 0.96-0.99).

CONCLUSIONS AND RELEVANCE

Cortisol is a neurobiological marker associated with teenaged-driving risk. As in other problem-behavior fields, identification of an objective marker of teenaged-driving risk promises the development of more personalized intervention approaches.

Variability in crash and near-crash risk among novice teenage drivers: a naturalistic study

OBJECTIVE

Using video monitoring technologies, we investigated teenage driving risk variation during the first 18 months of independent driving.

STUDY DESIGN

Driving data were collected on 42 teenagers whose vehicles were instrumented with sophisticated video and data recording devices. Surveys on demographic and personality characteristics were administered at baseline. Drivers were classified into 3 risk groups using a K-mean clustering method based on crash and near-crash (CNC) rate. The change in CNC rates over time was evaluated by mixed-effect Poisson models.

RESULTS

Compared with the first 3 months after licensure (first quarter), the CNC rate for participants during the third, fourth, and fifth quarters decreased significantly to 59%, 62%, and 48%, respectively. Three distinct risk groups were identified with CNC rates of 21.8 (high-risk), 8.3 (moderate-risk), and 2.1 (low-risk) per 10 000 km traveled. High- and low-risk drivers showed no significant change in CNC rates throughout the 18-month study period. CNC rates for moderate-risk drivers decreased substantially from 8.8 per 10 000 km in the first quarter to 0.8 and 3.2 in the fourth and fifth quarters, respectively. The 3 groups were not distinguishable with respect to personality characteristics.

CONCLUSION

Teenage CNC rates varied substantially, with distinct high-, moderate-, and low-risk groups. Risk declined over time only in the moderate-risk group. The high-risk drivers appeared to be insensitive to experience, with CNC rates consistently high throughout the 18-month study period, and the moderate-risk group appeared to learn from experience.

Teen driver risk in relation to age and number of passengers, United States, 2007-2010

OBJECTIVE

To provide updated estimates of the relationship between the number and ages of passengers present in a vehicle and the crash risk per mile driven of 16- and 17-year-old drivers.

METHODS

Data on crashes that occurred in years 2007-2010 and data on the number of miles driven in years 2008-2009 were examined. Rates of crash involvement and driver death per mile driven were estimated for 16- and 17-year-old drivers with no passengers; with 1, 2, and 3 or more passengers younger than age 21 (and no older passengers); and with at least 1 passenger aged 35 or older.

RESULTS

For 16- and 17-year-old drivers, having 1 passenger younger than age 21 (and no older passengers) was associated with 44 percent greater risk per mile driven of being killed in a crash, compared to having no passengers (relative risk [RR]: 1.44, 95% confidence interval [CI]: 1.01-2.04). Having 2 passengers younger than age 21 was associated with double the risk of being killed in a crash, compared to having no passengers (RR: 2.02, 95% CI: 1.36-2.99). Having 3 or more passengers younger than age 21 was associated with roughly quadruple the risk of being killed in a crash, compared to having no passengers (RR: 4.39, 95% CI: 1.45-13.31). The relative risk of being involved in any police-reported crash in the presence of young passengers followed a similar pattern; however, the differences in risks of being involved in any police-reported crash were smaller and were not statistically significant. Having at least 1 passenger aged 35 or older in the vehicle was associated with a 62 percent lower risk per mile driven of being killed in a crash (RR: 0.38, 95% CI: 0.24-0.60) and a 46 percent lower risk of being involved in any police-reported crash (RR: 0.54, 95% CI: 0.31-0.93) for 16- and 17-year-old drivers, compared to having no passengers.

CONCLUSIONS

These results show that although the overall number of teen driver fatalities has decreased substantially over the past several years, carrying young passengers is still a significant risk factor for young drivers. In contrast, carrying adult passengers is associated with significantly lower risk of crash involvement.

Chinese carless young drivers' self-reported driving behavior and simulated driving performance

OBJECTIVE

Carless young drivers refers to those drivers aged between 18 and 25 years who have a driver's license but seldom have opportunities to practice their driving skills because they do not have their own cars. Due to China's lower private car ownership, many young drivers become carless young drivers after licensure, and the safety issue associated with them has raised great concern in China. This study aims to provide initial insight into the self-reported driving behaviors and simulated driving performance of Chinese carless young drivers.

METHODS

Thirty-three carless young drivers and 32 young drivers with their own cars (as a comparison group) participated in this study. A modified Driver Behavior Questionnaire (DBQ) with a 4-factor structure (errors, violations, attention lapses, and memory lapses) was used to study carless young drivers' self-reported driving behaviors. A simulated driving experiment using a low-cost, fixed-base driving simulator was conducted to measure their simulated driving performance (errors, violations, attention lapses, driving maintenance, reaction time, and accidents).

RESULTS

Self-reported DBQ outcomes showed that carless young drivers reported similar errors, more attention lapses, fewer memory lapses, and significantly fewer violation behaviors relative to young drivers with their own cars, whereas simulated driving results revealed that they committed significantly more errors, attention lapses, and violation behaviors than the comparison group. Carless young drivers had a lower ability to maintain the stability of speed and lane position, drove more cautiously approaching and passing through red traffic lights, and committed more accidents during simulated driving. A tendency to speed was not found among carless young drivers; their average speed and speeding frequency were all much lower than that of the comparison group. Lifetime mileage was the only significant predictor of carless young drivers' self-reported violations, simulated violations, speed, and reaction time, whereas no significant predictor was found for young drivers with their own cars.

CONCLUSIONS

Carless young drivers had poorer driving performance and were more overconfident of their self-reported driving skills compared to those young drivers with greater access to vehicles. Given that the lifetime mileage positively predicted the simulated violations measure of carless young drivers, immediate interventions are needed to help them increase driving exposure and gain driving experience gradually before moving to more challenging on-road driving tasks. Supplemental materials are available for this article.

Peer influence predicts speeding prevalence among teenage drivers

IMPACT ON INDUSTRY

Preventing speed-related crashes could reduce costs and improve efficiency in the transportation industry.

OBJECTIVE

This research examined the psychosocial and personality predictors of observed speeding among young drivers.

METHOD

Survey and driving data were collected from 42 newly-licensed teenage drivers during the first 18months of licensure. Speeding (i.e., driving 10mph over the speed limit; about 16km/h) was assessed by comparing speed data collected with recording systems installed in participants' vehicles with posted speed limits.

RESULTS

Speeding was correlated with elevated g-force event rates (r=0.335, pb0.05), increased over time, and predicted by day vs. night trips, higher sensation seeking, substance use, tolerance of deviance, susceptibility to peer pressure, and number of risky friends. Perceived risk was a significant mediator of the association between speeding and risky friends.

CONCLUSION

The findings support the contention that social norms may influence teenage speeding behavior and this relationship may operate through perceived risk.

Graduated driver licensing research, 2010-present

This is the latest in a series of reviews of research on graduated driver licensing (GDL) published in the Journal of Safety Research, covering the period January 1, 2010-June 1, 2012 and works in progress. The intent is to keep researchers and policy makers current regarding the existing state of knowledge about GDL, and to identify information gaps and areas where clarification of research findings are needed. The recent research indicates that we continue to learn about ways to extend GDL benefits, but there remain important questions in need of further inquiry. In terms of impact on industry, the review provides guidance for the future GDL research agenda.

Mileage, car ownership, experience of punishment avoidance, and the risky driving of young drivers

OBJECTIVE

Young drivers are at greatest risk of injury or death from a car crash in the first 6 months of independent driving. In Queensland, the graduated driver licensing (GDL) program was extensively modified in July 2007 in order to reduce this risk. Increased mileage and car ownership have been found to play a role in risky driving, offenses, and crashes; however, GDL programs typically do not consider these variables. In addition, young novice drivers' experiences of punishment avoidance have not previously been examined. This article explores the mileage (duration and distance), car ownership, and punishment avoidance behaviors of young newly licensed intermediate (provisional) drivers and their relationship to risky driving, crashes, and offenses.

METHODS

Drivers (n = 1032) aged 17 to 19 years recruited from across Queensland for longitudinal research completed survey 1 exploring prelicense and learner experiences and sociodemographic characteristics. survey 2 explored the same variables with a subset of these drivers (n = 341) after they had completed their first 6 months of independent driving.

RESULTS

Most young drivers in survey 2 reported owning a vehicle and paying attention to police presence. Drivers who had their own cars reported significantly greater mileage and more risky driving. Novices who drove more kilometers, spent more hours each week driving, or avoided actual and anticipated police presence were more likely to report risky driving. These drivers were also more likely to report being detected by police for a driving-related offense. The media, parents, friends, and other drivers play a pivotal role in informing novices of on-road police enforcement operations.

CONCLUSIONS

GDL programs should incorporate education for the parent and novice driver regarding the increased risks associated with greater driving, particularly when the novice driver owns a vehicle. Parents should be encouraged to delay exclusive access to a vehicle. Parents should also consider whether their young novices will deliberately avoid police if they are aware of their location. This may reinforce not only the risky behavior but also young novices' beliefs that their parents condone this behavior.