Regional Evacuation Planning Using Computer Simulation Promise and Pitfalls

Computer simulation has long been used as a tool in the planning of vehicular evacuation of predetermined areas. Recent enhancements of the Federal Emergency Management Agency's (FEMA's) Integrated Emergency Management Information System (IEMIS) enable planners to apply a dynamic evacuation model to areas that may be determined on an ad hoc basis or by hazards whose location is not fixed, such as natural disasters. The regional evacuation analysis capability of IEMIS features map-based definition by the user of the area to be evacuated; map-based selection by the user of destinations and capacities; attribute-based selection by the user of classes of roadways to be included in the network; automated construction of a "first cut" network configuration; and automated calculation of vehicle loading rates onto the network, based on historic loading rate data from hurricane evacuations. At present the usefulness of this capability is limited by assumptions which are built into the model. Some user effort is required to correct these assumptions; but, the model facilitates some corrections by enabling the user to perform them graphically. The paper discusses the potential usefulness of this system to evacuation planners, problems that the user must address, and areas where improvement and additional research are needed.