Changes in Evacuation Decisions between Hurricanes Ivan and Katrina

Abstract

Hurricanes cause some of the worst traffic conditions, affecting evacuees’ ability to reach safety before they are subjected to high winds, heavy rain, and flooding. This paper is one of the few to use a panel survey to examine similar household decisions over consecutive hurricanes. The study focuses on Hurricanes Ivan and Katrina, which were of similar strength and followed similar paths, and is fairly comprehensive in the number of traffic-related decisions considered. Contingency tables, binary logit models, and Goodman and Kruskal's gamma measure were used to examine the effects of previous decisions on (a) whether to evacuate, (b) day of departure, (c) destination type and location, (d) number of household vehicles taken, and (e) reason for route selection. Through the statistical analyses, it was discovered that (a) to a great extent, citizens made the same decision to evacuate or stay for Katrina as they did for Ivan, and higher incomes were not significant in changing that decision; (b) some evacuees departed earlier, but most evacuees departed on the last day possible; (c) most evacuees selected the same type of accommodations and made the same inside-the-county-or-parish or out-of-the-county-or-parish decisions in consecutive evacuations; (d) the number of household vehicles used in the evacuation did not decrease; and (e) route guidance as a selection criterion did not depend on previous evacuation experience.