New Zealand Drivers Study: a follow-up study of newly licensed drivers

Injury Prevention as an Integral Part of Health System Reform Efforts: Lessons Learned from Recently Enacted Massachusetts Laws

Abstract-Injury is the leading cause of mortality in people younger than 44 years of age. Injury prevention laws and policies are not only effective in saving lives at a population level but are also remarkably cost-effective compared to most public health interventions. For example, the implementation of a stricter Massachusetts Graduated Driver Licensing Law in 2007 resulted in a very significant and rapid decrease in the rates of motor vehicle crashes of teenager drivers, saved thousands of lives, and resulted in more than $10 million dollars savings in health care costs over 5 years. We therefore suggest that trauma and injury prevention should be made a priority in any attempt at local, regional, or national health system reform.

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

AIM

To 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.

METHOD

This 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.

RESULTS

After 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.

CONCLUSION

There 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.

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

AIMS

To 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 DESIGN

The 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.

RESULTS

Thirty-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.

Learner driver experiences and crash risk as an unsupervised driver

OBJECTIVE

The purpose of this study was to describe the driving experiences of learner licensed drivers and examine the association between these driving experiences, associated factors, and on-road car crash involvement during the unsupervised restricted license stage.

METHODS

Data were drawn from a cohort investigation of newly licensed drivers. Information on demographic characteristics, personality, and risk behaviors was collected at the baseline interview. At the first follow-up interview (restricted license stage) study members were asked details about their experiences as a learner licensed driver: professional driving lessons, supervised driving, unsupervised driving, and driving courses in which they participated. During the second follow-up interview (full license stage), data were collected on crash involvement and driving exposure during the restricted license stage. Regression analysis was used to determine independent relationships between learner license driving experience variables and crash involvement.

RESULTS

After adjusting for demographic, personality factors, and driving exposure at the restricted license stage, increased time spent on the learner license was associated with a reduced risk of crash involvement during the unsupervised restricted license stage.

CONCLUSION

Results presented in this paper suggest that learner drivers in New Zealand should be encouraged to spend more time on their learner license to enable them to gain skills and experience to help reduce their crash risk when they are allowed to drive unsupervised.

IMPACT ON INDUSTRY

Compared with novice drivers who are on their learner license for the least amount of time, those who spend the most amount of time on their learner license have reduced risk of on-road crash involvement as an unsupervised driver. Learner drivers and their supervisors need to be aware of the length of time required for practice in order to reduce the risks of crash involvement when they are able to drive unsupervised (O'Brien et al., 2012). The recently introduced increase in the minimum driver licensing age in NZ, tougher restricted license stage driving test (aimed at encouraging 120 hours of supervised driving), and the Safe Teen driver campaign (NZ Transport Agency, 2012) are all strategies targeted at improving the safety of learner drivers. These strategies need to be evaluated to ensure they are achieving their goals.

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.