Spatiotemporal Analysis for the Impact of Traffic Incidents: Optimization Models Consistent with the Propagation of Shockwaves

Traffic incidents occurring on the road interrupt the smooth mobility of traffic flow and lead to traffic congestion. A fundamental issue in estimating the spatiotemporal impact of an incident is to ensure that the shape of the impact region is consistent with the propagation of shockwaves. In this chapter, we develop optimization models to guarantee such consistency. We first present an integer programming model with the differentiation of bi-level traffic status to estimate the spatiotemporal impact of a traffic incident. Then, we develop an optimization model by incorporating multiple congestion levels into the spatiotemporal analysis for the incident impact. The input to both models includes the historical speed on a given road and the occurrence time and location of the incident. Both models can then output the spatiotemporal impact region with guaranteed consistency. The validation of the models is conducted using both simulation and real data. Results not only show that both models can estimate spatiotemporal impact regions consistent with the propagation of shockwaves, but also demonstrate that the optimization model with multiple congestion levels can produce more accurate estimation of the delay caused by the incident when compared to the model with bi-level traffic status.