A computer-based information system for traffic accident analysis has been used in Gijteborg since 1971. This system processes accident and environment data from police reports and traffic measurements and facilitates continuous traffic regulations and road improvements. The number of traffic accidents per year in Gijteborg decreased from 6,000 to 3,900 during 1971-1980. The calculated profitability for traffic safety investments was 18%. If this corresponds to a reduction of the real costs of all traffic accidents is not clear.

A complementary registration of traffic accident casualties was started at the emergency hospitals in 1979. The purpose wasimproved injury classification and decreased number of not reported accidents, This hospital-based primary registration was expanded to include the medical and social consequences for patients injured in traffic accidents during three months in 1979. The time in hospital, the hospital costs, the time on sick-leave andcompensationsfrom the health insurance office indicated the accident outcome. Pedestrian accidents were by far the most important category according to this analysis.

Improved traffic safety depends among other things on reliable traffic and accident data. A more differentiated injury classification should improve the accident analysis and justify a continued use of this system. Medical information can be used in a more precise way to achieve this as indicated in this study.