DYMOD: Towards real time, dynamic traffic routing during mass evacuations

The next generation of evacuation planning models should leads us into real time traffic monitoring and, hopefully, control. In this paper we present some beginnings in this direction. Specifically, we describe the incorporation of the recently developed Dynamic Traffic Assignment model (Janson, 1991a) within a regional evacuation modeling procedure. Termed DYMOD (DYnamic MODel), the procedure employs a mathematical programming approach to allocate evacuees to destinations and routes on the basis of regularly updated traffic loading rates, and to dynamically allocate these evacuating vehicle volumes by updating traffic stream interactions on the network. These traffic streams may be simulated to conform to either a user specified evacuation plan, or to a dynamically updated traffic equilibrium pattern simulated to produce the least clearance time for the system as a whole. We report on progress and discuss extension of DYMOD into the realm of real time evacuation monitoring, replanning and control. The major purpose of the paper is not to present a fully developed methodology, but rather to stimulate further research into an area much in need of study.