Relocation of Children, Elderly, and Transit Dependents for a Daytime No-notice Evacuation in a Multimodal Transportation System

By Sirui Lui, Pamela Murray-Tuite, and Lisa Schweitzer

Under no-notice conditions with family members collecting dependents, the geographic location of these pickup points become a crucial factor to efficient evacuation. This paper presents a bi-level linear integer optimization model for facilities to relocate, optimally, dependents that need to be picked up. The program, solved using Lingo, is iterated with a traffic simulation model to obtain an optimal set of locations based on anticipated travel times with dependents relocated to those sites. Theentire methodology is applied to a sample application based on Chicago Heights, Illinois with three safety thresholds. The results found that the safe evacuation time threshold is quite important on implementing the strategy. When the safeevacuation threshold is tight, the relocation strategy is not effective;however, when it is adequate, relocating dependents of facilities increases the number of successful evacuation and decreases the total network evacuation time, and also significantly benefit those who rely on public transit to evacuate. Application of the proposed methodology to a certain area can assislocal decision-makers to take effective measures during no-notice evacuation and the relocation sites could be part of local evacuation management plans.