Identifying Bottlenecks in Roadway Networks in Hurricane Evacuation

Abstract

The existence of traffic bottlenecks limits the network capacity and leads to massive recurring and nonrecurring congestions during daily traffic peaks and in the critical event of an emergency evacuation. It is important to identify possible network bottlenecks to improve evacuation efficiency. Based on Newell’s simplified kinematic wave model, this paper presents a methodology to identify the network bottleneck links under hurricane evacuation. The methodology mainly includes three parts: (1) achieve traffic flow state updating and propagation based on the kinematic wave model; (2) estimate the evacuation demand using a hurricane evacuation response curve; and (3) identify the bottleneck links according to the mean and variance of the measurement of the degree of congestion. Hence, the proposed methodology is elaborated with a sample network, and the travel time distribution of identified bottleneck is analyzed. Furthermore, the method is applied to the bottleneck identification of a realistic network and results are obtained based on simulations using the methodology.