One of the primary purposes of traffic safety research is to describe the accident risk for different groups of road-users in different road and traffic conditions. In the R&D work carried out at the National Swedish Road and Traffic Research Institute, different measures for road accidents are tested in order to find suitable measures to be used in different decision procedures. The first requirement is that the accident measures shall allow relevant comparisons between different groups of road-users and/or different road and traffic conditions. When developing accident measures it is essential to define and to deduce traffic-measures that show strong correlations with the number of accidents. These traffic-measures are called risk exposures. Based on different problems, different types of risk exposure and methods for obtaining these are developed. The present traffic and road accident statistics and the r&d work conducted at the institute were chosen as a basis for the discussion of needs of risk exposures for accident analysis.
Abstract