Determinants of Departure Timing for Hurricane Matthew and Anticipated Consistency in Future Evacuation Departures

Abstract

This work investigated the factors affecting household choice of departure time during evacuations in Hurricane Matthew in 2016. Departure time estimates are needed to predict time-varying evacuation demand for use in simulation models and the development of evacuation traffic management strategies. The research team conducted a household survey after Hurricane Matthew in the Jacksonville, Florida, metropolitan area, with a total sample size of 588 respondents. Newly introduced factors were examined for significance throughout this work and were found to affect evacuation departure timing, such as uncertainty, family relationships, and cohesion. Uncertainty affects how certain the potential evacuees are about hurricane information such as hurricane impact location, whether they live in an evacuation zone, the timing of the hurricane and the evacuation destination and the route by which to get there, as well as the time needed to prepare for the evacuation. Family cohesion is related to decision-making agreement among household members and their preference to stay together in difficult situations. Such factors were poorly presented in previous literature. A Cox proportional-hazards model, a survival analysis technique used to study time till event, was used to model the evacuation departure timing, based on data from a post-Hurricane Matthew survey of Jacksonville, Florida, metropolitan area residents. The final model contained three significant variables, of which two are related to uncertainty and family cohesion. This study also used a binary logit model to examine evacuees’ retrospective preferences about whether they would have changed their evacuation timing. The preferred model contained five significant variables related to past experience, the type of evacuation order received, and the evacuation destination. This work opens several opportunities for additional studies on topics such as the stability of departure time; in addition, new factors presented here should be considered in future studies, such as certainty levels and household cohesion. Additional measures of experience could be incorporated to better understand the nuances of the experiences of different components of evacuation behavior.