Simulation Study of Impact of Evacuation Traffic on En-route Metropolitan Highway Network

摘要

In response to both natural and man-made disasters, more and more emergency evacuation plans have been put forward and consistently aims to move a large disaster affected population through a multimodal transportation network towards safer areas as quickly as possible. The objectives of this paper are (1) to verify the feasiblity of applying the DYNASMART-P model to simulation of traffic characteristics in both normal and emergency conditions for the urban transportation system in the Greater Jackson metropolitan area in Mississippi and (2) to develop and evaluate emergency strategies for a large scale evacuation of people under emergency conditions in the Greater Jackson area. In this paper, traffic network including Hinds, Madison and Rankin was built through the mesoscopic traffic-network planning and simulation model DYNASMART-P based on the dynamic traffic assignment methodology, and applied the model to a highway network on the route of the evacuation. The background OD demand as input for the simulation program was calibrated using observed traffic volume data collected in several critical routes of evacuation. An evacuation scenario was designed to study the impacts of the evacuating traffic from southeastern Louisiana to the Greater Jackson Metropolitan Area of Mississippi due to an assumed approaching hurricane disaster. Critically congested freeway segments under two evacuation intensity levels were identified based on the criterion of the average queue length percentage and level of service. The causes for the congestion of roads were analyzed and explained.