Estimating Influence Range of Unexpected Traffic Incidents Based on Improved Shock Wave Model

This paper studied the estimation of influence range of unexpected traffic incident by modifying the shock wave model. Firstly, the changing process of traffic states under unexpected traffic incident is analyzed by the shock wave model, and the concept of influence length is proposed. By the comparison analysis of evaluation index of microscopic simulation software VISSIM and the influence length model, the HGVs' rates and vehicle inputs are introduced into the model. The model is then divided into four stages: fluctuant stage, increasing stage, transitional stage and stable stage. After analyzing data, the segmentation model of the influence length is established under different types of unexpected traffic events, and the values of parameters are given respectively. This model provides a basis for engineering applications.