Abstract
It is necessary to compare national accident data with that from other countries to determine the underlying reasons for differing situations. Findings can then be used to learn about safety measures that have already proven effective in another country. Accident research covers the evaluation of trends, risk investigation as well as the identification of problem areas, the development of safety measures and their effectiveness. An outline is given of in-depth accident studies in the Hanover region of Germany where data on some 1000 accidents per annum are being collected. Examples are given of the use of data in the study of motorway safety, the use of safety belts and truck anti-lock braking systems.