Which Mode Should I Choose to Evacuate: Analyze and Synthesize Case Studies of Rapid-Onset Disasters

Abstract

Evacuate efficiently from risk areas during an imminent rapid-onset disaster can significantly impact life safety. However, understanding the impact of mode choice during evacuation remains insufficient. The recent development of computer simulation methods, such as agent-based model, provides opportunities for researchers and emergency managers to explore this question and test various scenarios to prepare and plan for future events. This study analyzes the simulation results from tsunami and wildfire evacuation simulation case studies and compares them with empirical evidence from questionnaire surveys and evacuation drills. The findings show that there is the “sweet spot” of mode split to reach the best evacuation outcome across different communities and transportation networks. Simulation studies uncover that total mortality reaches the lowest in both tsunami and wildfire evacuations when 70%–80% of people evacuate by foot, and the rest of the people evacuate by vehicles. However, the empirical survey data reveal people may not comply with the protective action recommendations. Our research also suggests that information and knowledge play a critical role in mode choice; thus, risk communication is still the cost-effective way to improve disaster response. The insights from this study can help emergency managers enhance the effectiveness of communities’ rapid-onset disaster evacuation plans and response.