Modelling developmental trajectories of novice drivers with high and low crash liability

Road traffic crashes are one of the greatest threats to public health, particularly for young people, with a substantial social and economic cost to society. Novice drivers are overrepresented in casualty statistics, with risk being particularly high in the first six months of their driving careers. There is evidence that both deficiencies in driving skills and decisions to adopt risky driving styles (e.g., speeding and overtaking in dangerous places) contribute to novice vulnerability. Averaged over all drivers, the rate of collisions declines rapidly over the subsequent 18-24 months but does not plateau until drivers reach approximately 30 years of age. While the prevalence of road traffic injuries for novice drivers is well documented, there is still relatively little understanding of why crash liability is particularly high in the first three months of driving before decreasing steadily over time. Rather than all drivers following the same developmental pathways, we believe different types of novice driver will follow different trajectories of crash risk and behavioural development. For example, our preliminary analyses of the proposed dataset indicate that crash involvement differs on the basis of risky attitudes at the time of passing the driving test. Participants scoring in the top third of a risky attitudes scale showed an initially high rate of crash involvement that declined steeply after the first 6 months. The participants with less risky attitudes were at lower initial risk of crash and their risk did not show a similar pattern of decline. Our available resources meant our preliminary analysis could only use basic techniques. The full project will employ advanced statistical modelling techniques to identify sub-groups of novice drivers following different developmental trajectories of crash involvement and driver behaviour. We will then explore the extent to which trajectory is predicted by modifiable risk factors such as driving behaviour and experiences in learning to drive. These results will guide policy on education, assessment and management (e.g., graduated licensing) of learner and novice drivers to encourage drivers onto the lower risk trajectories rather than the higher risk.

The proposed research will have wide ranging implications for road safety. The main beneficiaries of the project will be road safety professionals, policy makers, and academic researchers, with future newly-qualified drivers the ultimate beneficiaries.

Road safety professionals will be able to use the findings to better inform the development of targeted interventions aimed at reducing the elevated crash risk of newly-qualified drivers in the UK and internationally. Results of the analysis will be disseminated to the road safety community through a series of presentations at conferences and seminars, and via a specially designed project website which will be promoted through the online road safety network (e.g., roadsafetygb.org.uk, airso.org.uk etc). The results can be integrated into pre-test interventions in order to try to reduce potential crash liability prior to the start of drivers' licensed driving career. The project aims to highlight behaviours that predict membership of higher risk driver groups, and knowledge of factors associated with increased crash liability can be used by driver training practitioners to raise awareness of problem behaviour with learner drivers. Furthermore, the research will inform local government initiatives to prepare novice drivers for risks they might face on the road, such as the Learn Safe Drive Safe programme run by Sheffield City Council. The project team have considerable connections with the road safety community, which will facilitate dissemination of findings.
There will also be considerable implications for transport policy makers. The research findings will inform road safety policy, and provide an evidence base for decisions relating to newly-qualified drivers. The use of group-based modelling will also provide novel evidence on the provision and timing of intervention strategies and driver training programmes. Dissemination will be achieved through a number of ways including a one-day seminar held at the Transport Research Laboratory (TRL), with an invited audience of key individuals and organisations from the road safety community, including policy makers and researchers. The project will also provide an evidence-base with which to inform debates regarding post-test supervision/training, particularly regarding Graduated Driver Licensing (GDL) systems, through exploration of the time course of risky driving behaviour and its relationship with elevated crash involvement. The results will have implications for the optimal lengths for such schemes in order to achieve reductions in traffic casualties.

The benefits for academic researchers will be in advancement in understanding the factors that are associated with the elevated crash risk, and the underlying behaviours related to the rapid decrease in crash liability over the first few months of licensure. There is limited theoretical work on novice driver behaviour, and the results of longitudinal analysis will contribute to the development of theoretical model to help explain the variance in behaviour among novice drivers. This will be achieved through publication of the research in high impact journals, and presentations at international conferences.