Study on trac conflict prediction model of closed lanes on the outside of expressway

Abstract

Due to the randomness and weak symmetry of trac accidents occurring in the expressway maintenance operation area, it is dicult to use the number of trac accidents to evaluate the safety of maintenance operation areas. In this paper, the trac characteristics and trac conflicts of the maintenance operation area with the lane closed on the outside of the two-way four-lane expressway are studied. By using the statistical method, the distribution of vehicle speed and time headway in dierent areas of the maintenance operation area are analyzed, and the queuing characteristics of vehicles in the upstream transition zone of the expressway are determined. Based on improved time to collision (TTC) model, the trac conflict severity of expressway maintenance operation area is divided. The negative binomial distribution is used to establish a trac conflict prediction model for the enclosed maintenance area of the outer lane of the expressway, and the validity of the trac conflict prediction model is verified based on the average absolute error percentage (MAPE). The research results show that: when the 0 < TTC < 1.3 s, the trac conflict is serious conflict; when 1.3 s < TTC, the trac conflict is non-serious conflict. Furthermore, the trac conflict prediction model has high accuracy, the MAPE of the warning area and the upstream transition area are 10.8% and 5.0%, respectively.