Quantifying the Severity of Traffic Conflict by Assuming Moving Elements as Rectangles at Intersection

To evaluate safety in intersections and find the relationship between conflict and accidents, a quantitative method for the severity of traffic conflict at intersection was proposed. Moving elements were assumed as rectangles. By using technology of imaging processing, kinematics parameters of vehicles were obtained. Supposed that movement units keep moving with current motion state, traffic conflict and time to collision (TTC) were determined using iterative method and analyzing positions of rectangles’ vertexes. According to the analysis of traffic conflict and brake performance of vehicles, non-complete braking time (TB) was selected to be critical value of conflict severity. Taking TTC and TB as parameters, quantitative value (Qs) was established. The severity of traffic conflict was quantified and classified by analyzing TTC and Qs. A case in Beijing was analyzed. The results indicated that quantitative result accorded with practical situation, and this method could be used in conflict detection and quantifying the severity of traffic conflict accurately.