A systemic traffic accident model

Abstract: Accident models are essential for all efforts in safety engineering. They influence theinvestigation and analysis of accidents, the assessment of systems and the development ofprecautions. Looking at accident statistics, the trend for Swedish roads is not pointing towardsincreased safety. Instead, the number of fatalities and accidents remains stable, and thenumber of injuries is increasing. This thesis proposes that this deterioration of road safety isdue to the utilization of inadequate traffic accident models. The purpose of the thesis is todevelop an adequate traffic accident model. This is done in two steps. The first step is toidentify a proper type of general accident model. The second step is to adapt the generalaccident model to road traffic. Two reviews are made for this purpose. The first reviewidentifies different categories of accident models. The second review surveys eleven existingtraffic accident models. The results of these surveys suggest that an adequate accident modelfor modern road safety should be based on the systemic accident model. Future work willfocus on the development of a risk assessment method for road traffic based on the systemicaccident model.