New Zealand Drivers Study Research Articles

Associations of repeated high alcohol use with unsafe driving behaviors, traffic offenses, and traffic crashes among young drivers: Findings from the New Zealand Drivers Study

ABSTRACTObjective: The objective of this study was to describe self-reported high alcohol use at each of the 3 licensing stages of graduated driver licensing and its relationship to drink-driving behaviors, intentional risky driving, aggressive driving, alcohol traffic offenses, non-alcohol traffic offenses, and traffic crashes.Methods: The New Zealand Drivers Study (NZDS) is a multistage, prospective cohort study of newly licensed drivers interviewed at all 3 stages of the graduated driver licensing system: learner (baseline), restricted (intermediate), and full license. At each stage, alcohol use was self-reported using the Alcohol Use Disorders Identification Test (AUDIT-C), with high alcohol use defined as a score of ≥4 for males and ≥3 for females. Sociodemographic and personality data were obtained at the baseline interview. Alcohol-related, intentional risky, and aggressive driving behaviors were self-reported following each license stage. Traffic crashes and offenses were identified from police records. Crashes were also self-reported.Results: Twenty-six percent (n = 397) reported no high alcohol use, 22% at one license stage, 30% at 2 stages, and 22% at 3 stages. Poisson regression results (unadjusted and adjusted) showed that the number of stages where high alcohol use was reported was significantly associated with each of the outcomes. For most outcomes, and especially the alcohol-involved outcomes, the relative risk increased with the number of stages of high alcohol use.Conclusions: We found that high alcohol use was common among young newly licensed drivers and those who repeatedly reported high alcohol use were at a significantly higher risk of unsafe driving behaviors. Recently introduced zero blood alcohol concentration (BAC) should help to address this problem, but other strategies are required to target persistent offenders.

Participation in driver education/training courses during graduated driver licensing, and the effect of a time-discount on subsequent traffic offenses: Findings from the New Zealand Drivers Study

IntroductionThe New Zealand GDL includes a time-discount at the restricted license stage, for attendance at an approved driver education course. This is despite international evidence showing that earlier licensure associated with a time-discount can increase risk for newly licensed drivers. ObjectiveTo examine participation in driver education courses and especially those that qualify for a time-discount; compare the profiles of course participants with non-participants; examine reasons for participation; and examine the association between a time-discount and traffic offenses once fully licensed. MethodThis study was based on the New Zealand Drivers Study (NZDS), a prospective cohort study of newly licensed drivers. Data on driver education courses were obtained at the full license interview (n=1763), driver license and traffic offense data from the NZ Driver Licence Registry, and other data at the NZDS interviews. Results94% had heard of and 49% (n=868) participated in a defensive driving course (DDC). No other course had more than 1% participation. Compared with the others, the DDC group were young, non-Māori, and from an area of relatively low deprivation. Through GDL, the DDC group were relatively more compliant with the conditions, and less likely to crash or receive a traffic offense notice. The groups did not differ on personality, alcohol and drug use. The reason most (85%) attended a DDC was to get their full license sooner; 86% (n=748) received a time-discount. The time-discount group were 40% more likely to receive a traffic offense notice on their full license; this reduced to 10% after controlling for other factors. Conclusion and practical implicationsThe results of this study, when viewed in conjunction with other NZ crash evidence, indicate that a time-discount should not be given for completing a DDC or Street Talk course.

Pre-licensed driving experience and car crash involvement during the learner and restricted, licence stages of graduated driver licensing: Findings from the New Zealand Drivers Study

ObjectiveThe aim of this study was to determine whether pre-licence driving experiences, that is driving before beginning the licensing process, increased or decreased crash risk as a car driver, during the learner or the restricted licence stages of the graduated driver licensing system (GDLS). MethodStudy participants were 15–24 year old members of the New Zealand Drivers Study (NZDS) – a prospective cohort study of newly licensed car drivers. The interview stages of the NZDS are linked to, the three licensing stages of the GDLS: learner, restricted and full. Baseline demographic (age, ethnicity, residential location, deprivation), personality (impulsivity, sensation seeking, aggression) and, behavioural data, (including pre-licensed driving behaviour), were obtained at the learner licence interview. Data on distance driven and crashes that occurred at the learner licence and restricted licence stages, were reported at the restricted and full licence interviews, respectively. Crash data were also obtained from police traffic crash report files and this was combined with the self-reported crash data. The analysis of the learner licence stage crashes, when only supervised driving is allowed, was based on the participants who had passed the restricted licence test and undertaken the NZDS, restricted licence interview (n=2358). The analysis of the restricted licence stage crashes, when unsupervised driving is first allowed, was based on those who had passed the full licence test and completed the full licence interview (n=1428). ResultsAfter controlling for a range of demographic, personality, behavioural variables and distance driven, Poisson regression showed that the only pre-licence driving behaviour that showed a consistent relationship with subsequent crashes was on-road car driving which was associated with an increased risk of being the driver in a car crash during the learner licence period. ConclusionThis research showed that pre-licensed driving did not reduce crash risk among learner or restricted licensed drivers, and in some cases (such as on-road car driving) may have increased risk. Young people should be discouraged from the illegal behaviour of driving a car on-road before licensing.

Unsupervised driving by learner licence holders: Associated characteristics and crash risk

AimsTo determine: (a) the association between socio-demographic, and behavioural factors and compliance with supervised driving condition as a learner licensed driver, (b) whether unsupervised driving as a learner licence holder was associated with elevated crash risk while holding a learner licence. Study designThe study population was the New Zealand Drivers Study (NZDS) cohort, a prospective cohort study designed to explore the relationship between a comprehensive range of driving and traffic safety related factors and subsequent traffic crashes and convictions among newly licensed drivers. ResultsThirty-one percent of the study sample was non-compliant at least once with the supervised driving condition. Many socio-demographic and behavioural risk factors were independently associated with unsupervised driving. The strength of the associations was greatest for those with relatively high levels of unsupervised driving (13+ trips). High distance driven showed the strongest relationship: RR 8.91 (95% CI 5.27–15.07). Unsupervised driving was associated with increased risk of crash: 1–12 trips: RR 1.84 (1.29–2.61), and 13+ trips: RR 2.71 (1.94–3.80).Given that a significant portion of learner licence holders report driving unsupervised and those that violate this condition the most are more likely to crash, evaluation of strategies designed at improving compliance with learner licence supervised driving condition should be a research priority.

Parental influence on adolescent compliance with graduated driver licensing conditions and crashes as a restricted licensed driver: New Zealand Drivers Study

AimTo examine the influence of parental knowledge of, and support for graduated driver licensing (GDL) conditions, parental management of adolescent driving and parental driving behaviour on adolescent compliance with GDL conditions and crashes as a restricted licence driver. MethodThis research was part of the New Zealand Drivers Study (NZDS), a prospective cohort study of 3992 newly licensed car drivers. NZDS participants were recruited at the learner licence stage, with follow-up aligned with the GDL stages. At the restricted licence stage 1200 parents of NZDS adolescents, aged 15–17 years at learner licensure, were recruited and completed interviews. 895 of these adolescents progressed to their full licence and completed the full licence interview. These 895 parent–adolescent pairs were the study population in this research. Topics examined included parental knowledge of, and support for GDL conditions, management of adolescent driving (driving rules, adolescent vehicle ownership, delaying licensure), and their own driving behaviours. Outcomes examined were adolescent compliance with GDL restricted licence conditions (night-time and passenger), and crashes as a driver during the restricted licence stage. ResultsAfter controlling for other variables, factors independently associated with adolescent low compliance with GDL conditions were: low parental knowledge of conditions, parents’ implementing few driving rules, adolescent vehicle ownership, and parent crash involvement. Factors independently associated with adolescents being a crash involved driver were: parents’ actively delaying licensure, adolescent vehicle ownership, and parent crash involvement. ConclusionThere is increasing recognition of the importance of parental involvement in adolescent driving. The results show that parents are influential in determining adolescent compliance with GDL and risk of crash. Parents can have considerable positive influence on their adolescent's driving through ensuring compliance with the components of GDL, limiting vehicle ownership and by modelling safe driving behaviours.

DOES PRE-LICENSED DRIVING EXPERIENCE AFFECT CRASH RISK AS AN UNSUPERVISED RESTRICTED LICENSED DRIVER? FINDINGS FROM THE NEW ZEALAND DRIVERS STUDY

BackgroundThere is a popular notion that driving experience before commencing licensing may help improve driver safety as a newly licensed driver. The limited empirical evidence available suggests that the opposite...

Nonprogression Through Graduated Driver Licensing: Characteristics, Traffic Offending, and Reasons for Nonprogression

Objectives: In a graduated driver license environment, (1) compare nonprogressors with progressors in terms of prelearner license sociodemographic and behavioral factors, (2) determine whether nonprogressors were more likely to have had a traffic offense than progressors, and (3) determine why nonprogressors chose not to progress. Methods: Our study population was that of the New Zealand Drivers Study (NZDS), a prospective cohort study of newly licensed drivers designed to explore the relationship between a comprehensive range of driving and traffic safety related factors and subsequent traffic crashes and convictions among newly licensed drivers. Nonprogressors, those who had not progressed from a learner to a restricted license 2 years after being eligible to do so, were compared with progressors in terms of their sociodemographic, behavioral characteristics, and traffic offense outcomes. Results: Nonprogressors represented 38 percent of the cohort and had different sociodemographic and behavioral profiles than progressors. A delay in progression was associated with reduced risk of being a traffic offender. The primary reasons reported for nonprogression were too lazy or busy or limited access to the means to drive. Conclusion: Before restricting how long a novice driver can hold a learner license, as has been suggested by the Ministry of Transport, consideration should be given to the potential increased risk of offending once unsupervised driving is permitted.

Risk perception and risky driving behaviours of adolescents and their parents: New Zealand drivers study

Background and AimA growing body of research indicates that driving behaviours and beliefs of parents can influence their child's driving. However, these studies have been limited by small sample sizes,...