Over a two-year period, in-depth crash-injury investigations were performed on a comprehensive sample of accidents involving nearly two and a half thousand car occupants. The study covered a fixed geographical area, being based on the catchment area of one large accident hospital. Included in the study were all car occupants, including those escaping injury, who were involved in any accident where one or more casualties attended the hospital. The sample was, therefore, as closely representative of the whole accident injury situation as was possible.

This paper shows the relative frequencies of the different types of accident configuration and the associated risks of injury for the different seating positions and use or non-use of seat belts. The different patterns and mechanisms of injury are given for the basic impact types and because of the comprehensive nature of the sample it has been possible to put the severe but less frequent injuries into perspective with those more commonly occuring. For the more important causes of injury in terms of clinical severity or frequency, distributions of injury severities are given along with details of the specific types of injury sustained.