MTO Factors Contributing to Road Accidents at Intersections

At present, work in road traffic safety is expanding from injury prevention to include also accident prevention. For accident preventive measures to be effective, knowledge is needed about common causal factors that contribute to the occurrence of accidents. This paper aims towards identification of such common factors for a specific subset of all road accidents, namely intersection accidents. The data used for the study consists of in-depth investigation material from sixteen intersection accidents that have been investigated by a multi-disciplinary accident investigation team. Data analysis was performed using DREAM, a MTO based accident investigation method. The results indicate that cognitive bias, hidden information, inadequate design of traffic environment, and competing task are common contributing factors of intersection accidents. Also, the distribution of factors for different collision path scenarios was studied, and several patterns in the distribution were discovered. These patterns were then compared to the results of another study with a similar aim, but based on database statistics rather that in-depth data. The conclusion of the comparison is that the DREAM method, in combination with in-depth accident data, provides a deeper and more detailed insight into how and why different factors contribute to accidents, and these insights are well suited for accident preventive work