Assessing the Effectiveness of Flexible Response in Evacuations

Abstract

The past 20 years have seen significant improvements in the way regional mass evacuations are carried out in the United States. Today’s use of phased evacuation orders, contraflow, and citizen-assisted transit evacuations have come about as lessons learned from previous evacuations and have led to improvements in later ones. This paper summarizes a study to examine what may be a future step in this improvement process: the concept of flexible evacuation responses to major catastrophic hazards. Within this idea, evacuation plans would be developed in which the timing, direction of movement, and regional traffic-management plans would be changed based on the characteristics (e.g., strength, speed, movement, etc.) of a particular threat. This study was carried out using an integrated model that combines a calibrated evacuation demand model with a calibrated microscopic simulation model to evaluate a set of flexible evacuation plans for four theoretical hurricane conditions. The experimental results showed that even simple alterations to a single, static, one-size-fits-all-scenarios plan had significant benefits to the movement of traffic. In addition, such improvements could provide over $400,000 in fuel savings over the existing static plan. Whereas this research was based on evacuation from a hurricane, it is expected that similar results could be attained for evacuations from other threats.