Although crash rates increase substantially when teens make the transition to unsupervised driving, little is known about the changes that occur during this critical period. The present study examined how the internal driving environment (e.g., passengers, belt use), external driving environment (e.g., time of day, traffic density), and the nature of driving incidents differs between the first four months of the learner period and the first six months of unsupervised driving. An event data recorder (Drivecam) was installed in the vehicles of 50 families of beginning teenage drivers at the outset of the learner stage. The recorders were re-installed in the vehicles of 38 of these families when the teen obtained an intermediate license. The analyses in this report are based on these 38 teens. The availability of event-based data from the same families during both the learner permit stage and the intermediate licensing stage provided a unique opportunity to explore how the driving environment and driving behaviours differ during these two periods. The findings suggest that driving conditions do appear to differ between the learner stage and the high risk initial period of unsupervised driving. During the intermediate license stage, a greater percentage of driving clips occurred in darkness or inclement weather than during the learner stage. In addition, loud, potentially distracting music was noticeably more common after teens obtained an intermediate license. The presence and composition of passengers also changed dramatically, shifting from parents and siblings during the learner stage to primarily friends. Notably risky or worrisome driving incidents were rare during both the learner and intermediate license stages. A relatively small number of teens accounted for many of the incidents during the intermediate license stage. Although this study provides important, new evidence on how the driving circumstances and conditions change when teens begin driving without a supervisor, there are inherent limitations of the study due to the sample size and underlying methods that are described in the study. (Author/publisher)
Abstract