The duration depends on four stages of traffic accidents, including discovery/detection, response, disposal and recovery. Due to the limited data or resources, it is difficult to quantify the detection time. However, the detection time appears to be the most important component, since it is responsible for the first and the majority of the duration. The distribution mode of the detection time for highway traffic accidents is researched. Some factors and the discretization method are discussed to show the influence rules. Finally, an example of verification is carried out in Shaan’xi province. The proposed discretization method is effective as the calculated result.

CICTP