Agent-based micro-simulation of staged evacuations

Abstract

One of the most critical issues for an evacuation is to design an effective evacuation strategy that could lead to the reduction of the total evacuation time. Previous studies demonstrated the advantage of certain staged evacuation strategies over the simultaneous evacuation strategy. This study aims to identify an effective yet feasible evacuation zoning structure for staged evacuation strategies of Galveston Island. The proposed zoning structure attempts to reduce the traffic pressure at the beginning of the IH-45 bridge, the only exit to the mainland. This study employs VISSIM, an agent-based microsimulation software package, to simulate the evacuation process. The sensitivity of the total evacuation time to time intervals between notifications of the staged evacuation is examined. The findings suggest that when an appropriate interval is selected, the staged evacuation using the proposed zoning structure is more effective than a simultaneous evacuation. A longer span between notifications could reduce the evacuation time of the last vehicle, but does not necessarily lead to the reduction of the total evacuation time.