Developing Large-Scale Emergency Evacuation Capabilities in Response to Airborne Hazmat Release

Large-scale evacuation is called for when a natural (such as hurricane) or man-made (such as hazmat release or even dirty bomb) extreme event strikes a populated area so that the population is exposed to immediate or foreseeable life-threatening danger. Evacuating a large population is an extremely complicated and difficult task, which primarily relies on efficient utilization of intermodal transportation systems, and effective evacuee evacuation schemes. In an unexpected extreme event scenario, evacuating a large population could be devastating. Lacking proper coordination among evacuees in choosing evacuation times and routes, evacuees often get stuck in the roadway gridlocks for an excessive period of time. This could lead to significant life and property loss that would have been otherwise saved. This paper presents a research that is aimed at developing an emergency evacuation modeling capability, which entails a careful integration of an optimal evacuation time and route choice model, as well as a traffic simulation model. The optimal evacuation time and route choice model is a non-linear mathematical programming model. The traffic simulation model is a meso-scopic simulation model that simulates all the vehicles in the network in a computational efficient manner. The El Paso area network has been constructed as a test bed for the case study in which a toxic airborne hazmat release incident occurs in the morning peak hours; thus calls for a large-scale city wide evacuation. Experiment results conclude that the proposed methodology provide a critical operational planning capability for large-scale emergency evacuation management. Significant insights about evacuating citizens out of central El Paso are also provided.