Older drivers: Crash involvement rates and causes

Abstract

This report presents an analysis of the claims that older drivers are over-represented in road crashes and an examination of the nature of the ‘older driver problem’ in so far as it exists. Four different types of crash rates (crash numbers, crashes per head of population, crashes per licensed driver, crashes per distance driven) are considered, with emphasis placed on problems in interpretation of the various crash rates and what information can be derived from each of them. It is concluded that the crash rates of most importance are total crash numbers and crashes per licensed driver, neither of which were found to feature an over-representation of older drivers. Also addressed in the report is the question of whether the increase in crash rates per distance driven might be a phenomenon associated with older drivers as a whole, or one associated with specific subgroups of older drivers whilst the remainder maintain the relatively low crash rates of middle-aged drivers. Although there are arguments to support the claim that there are high risk subgroups of older drivers, it is nevertheless concluded that high risk older drivers cannot be identified in mass crash data. A third section of the report contains an analysis of a sample of crashes involving older drivers that were investigated as part of an in-depth study into rural road crashes. The factors other than the driver which contributed to the occurrence of the crashes are discussed, illustrating the importance of appropriate road infrastructure for reducing older driver crashes.