It is well known that young and inexperienced drivers incur a higher risk of traffic accidents than more experienced drivers. It has also been shown that there is both an `age' and an `experience' component in the decrease of accident risk taking place during the first years of license driving. The demonstration that `experience' results in reduced risk independently of age raises several interesting issues related to the process of `learning safe driving behaviour'. What is it actually drivers are learning, which makes them drive more safely? Such knowledge may have important implications for efforts to increase safety by driver education and training. So far, most studies have addressed the issue of accident risk of young drivers on a rather coarse time scale, looking at accident risk on a year basis at best. To reveal the differences in safe driving between inexperienced and experienced drivers, it may be useful to study their risk developed on a smaller time scale, since the typical characteristics of inexperienced drivers are most likely to be detected shortly after they get their licence. Changes in behaviour as a consequence of increased experience are therefore likely to be larger during this early period than later on. It may also be useful to analyse the changes in crash risk separately for different crash types, since the lack of driving experience may have different effects on different types of crashes. In order to such study short-term changes in driver crash risk, the author carried out a study where crash and exposure data for novice drivers were collected on a monthly basis during the first 18 months after licensing. The study was part of a larger project with the aim of evaluating effects on changes in the driver training and licensing regulations. This paper will, however, focus only on describing the general risk development, and not on the effects of driver training. (A)
Abstract