Crash Risk and Risky Driving Behavior Among Adolescents During Learner and Independent Driving Periods

PURPOSE

Novice adolescents' crash rates are highly elevated early in licensure, despite substantial practicedriving during the learner period. The objectives of this study were to examine the variability in measures of driving risk among adolescents during the learner and early independent driving periods and evaluate how risk varies by driving experience, gender, time of day, and road surface conditions.

METHODS

Objective driving data were collected in a naturalistic cohort study of 90 adolescent drivers with learner driving permit and 131 experienced adult drivers. Participants' private vehicles were equipped with data acquisition system documenting driving kinematics, miles driven, and video recordings of the driver and the driving environment. Crash/near-crash (CNC) and kinematic risky driving (KRD) rates were calculated during the learner and early independent driving periods by gender (female/male), time of day (day/night), and road surface conditions (wet/dry) for adolescents and adults.

RESULTS

CNC and KRD rates of adolescents were similar to adult drivers during the learner period (CNC: incident rate ratio [IRR] = 1.67, confidence interval [CI] = .98-2.82 and KRD: IRR = 1.04, CI = .78-1.40, respectively), but dramatically higher in the first year of independent driving (CNC: IRR = 6.51, CI = 4.03-10.51 and KRD: IRR = 3.95, CI = 2.96-5.26, respectively), and particularly elevated the first 3months of licensure. Adolescent KRD rates were higher for males than females and invariably higher than adult rates during day and night, wet and dry conditions.

CONCLUSIONS

While the learner driving period was relatively safe for adolescents, the transition to independent driving was typified by a dramatic increase in risk among adolescents that was higher than adult rates overall and under varying driving conditions.

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.

Effectiveness of Parent-Focused Interventions to Increase Teen Driver Safety: A Critical Review

PURPOSE

We critically reviewed recent parent-directed teen driving interventions to summarize their success in meeting stated goals; identify promising intervention components and knowledge gaps; aid in the selection, adaptation, and dissemination of effective interventions; and guide future research efforts.

METHODS

We focused on interventions that included a direct parent component, explicitly stated outcomes related to the teen and/or their parents, were evaluated for parent or teen outcomes, targeted drivers younger than the age of 21 years, and had at least one evaluation study published since 1990 and in English. We conducted a comprehensive systematic search of 26 online databases between November 2013 and January 2014 and identified 34 articles representing 18 interventions.

RESULTS

Several interventions-in particular, those that had an active engagement component, incorporated an in-vehicle data recorder system, and had a strong conceptual approach-show promise in improving parental supervisory behaviors during the learner and early independent phases, increasing teen driver skill acquisition, and reducing teens' risky driving behaviors.

CONCLUSIONS

We identify essential characteristics of effective parent-involved teen driving interventions and their evaluation studies, propose a comprehensive and multitiered approach to intervention, and discuss several research areas and overarching issues for consideration.