Authors: Ying Liu , Xiaorong Lai , and Gang-len Chang
Journal: Journal of Transportation Engineering, Volume 132, Issue 10, pp. 800-807 (October 2006)
This paper presents a two-level integrated optimization system for use in generating the candidate set of optimal evacuation plans that serve as the input for simulation-based evacuation systems. In the proposed system, the high-level optimization aims to maximize the throughput during the specified evacuation duration, and the low level intends to minimize the total travel time as well as waiting time for the entire operation if the specified duration is sufficient for evacuating all demands. To effectively represent traffic flow relations with mathematical formulations, this paper employs the cell transmission concept, but with a revised formulation for large-scale network applications. The performance of the proposed models and their applicability has been tested with a microscopic simulation program that replicates the Ocean City evacuation network. Evaluation results from these numerical studies have demonstrated the promising properties of the proposed integrated optimization system.