Role of Transit in Carless Evacuation Planning

Abstract

During evacuations, the needs of transit-depended and carless populations require special attention and add to the complexity of evacuation logistics. The objective of this paper is to examine the role of transit in the evacuation of carless populations as part of a comprehensive evacuation plan. For this purpose, a case study is presented describing the development of a large-scale simulation/optimization model for the Birmingham, Alabama region that considers evacuation of carless populations with transit in the event of flooding. Flooding evacuation studies can be useful in evaluating various alternatives to evacuate people, identifying alternative routes based on historical experience of flooded areas and supporting optimal assignment of rescue personnel and optimization of their routes. The paper first provides a synthesis of the state of practice in carless evacuation using transit. Then the study methodology is presented, and details are offered on model selection, development, and testing; study site characteristics; study scenarios modeled; and related assumptions. Study scenarios consider vehicle evacuation with and without evacuation of carless populations from the affected area to nearby shelters using transit assets. Consideration is given to the fact that some network links would not be accessible because of the flooding, and thus lane closures are modeled in the study scenarios to increase the realism of the model. The paper demonstrates the opportunities and requirements related to the use of transit for local emergency evacuations while best serving the needs and interests of carless populations and the public at large.