Survival Analysis of Urban Traffic Incident Duration: a Case Study at Shanghai Expressways

Traffic incident duration is one of the most important parameters to describe traffic congestion intensity of expressways. Numerous measures have been developed to describe the characteristics of traffic incidents and the vast majority of these studies use data mining. Though they inform us the objective elements of the environment may influence traffic incident, the how question-via what way these physical features affect traffic incident-is largely unexplored. Based on the historical traffic data of viaduct expressways in Shanghai, this paper introduces survival analysis into the analysis of traffic incident mechanism, and a survival Analysis-Based Modeling of urban traffic incident duration is presented. This model first analyzes the time attributes of many traffic incident samples, and employs nonparametric regression based on KaplanMeyer model to estimate hazard-based traffic incident duration. Then, the key influence factors of traffic incident are divided into five types and the spatial-temporal distribution characteristics of traffic incident duration time are analyzed. Finally, COX regression is used to model the co-evolution between multidimensional influencing factors of traffic incident duration. The key characteristic parameters of expressway incident management in Shanghai are optimized to analyze the evolution mechanism of incident duration. The result shows that, for different type of influencing factors, the spatial-time distribution of traffic incident duration in Shanghai expressway exists significant difference, and factors like day & night, incident type, related vehicle number, related lane number, location, bottleneck and trailer will affect the incident duration significantly.