Evacuations

Power Trips: Early Understanding of Preparedness and Travel Behavior During California Public Safety Power Shutoff Events

Stephen Wong, PhD, Jacquelyn Broader, Susan Shaheen, PhD
2022

Recent wildfire risks in California have prompted the implementation of public safety power shutoff (PSPS) events, procedures enacted by utility operators to de-energize parts of the electrical grid and reduce the likelihood of wildfire ignition. Despite their yearly occurrence, PSPS events are severely understudied, and little is known about how these events impact disaster preparation activity, travel behavior, and transportation systems. With growing wildfire risks in North America and beyond, PSPS events require immediate and thorough research to reduce their negative externalities and...

Double the Trouble: A Playbook for COVID-19 and Evacuations

Stephen Wong, PhD, Jacquelyn Broader, Adam Cohen, Susan Shaheen, PhD
2021

Evacuation and response plans require thoughtful strategies that build mandatory evacuation order compliance, reduce vehicular congestion, and increase social equity for disadvantaged populations. However, the novel coronavirus (COVID-19) pandemic coincided with a series of devastating disasters in 2020 that have required mass evacuations, leading to several new compounding effects (i.e., “double the trouble”). Strategies typically used in evacuations (e.g., high-capacity vehicles and public congregate shelters) and movements of people (e.g., evacuees, first responders, and...

Compliance, Congestion, and Social Equity: Tackling Critical Evacuation Challenges through the Sharing Economy, Joint Choice Modeling, and Regret Minimization

Stephen Wong
2020

Evacuations are a primary transportation strategy to protect populations from natural and humanmade disasters. Recent evacuations, particularly from hurricanes and wildfires, have exposed three critical evacuation challenges: 1) persistent evacuation non-compliance to mandatory evacuation orders; 2) poor transportation response, leading to heavy congestion, slow evacuation clearance times, and high evacuee risk; and 3) minimal attention in ensuring all populations, especially those most vulnerable, have transportation and shelter. With ongoing climate change and increasing land...

A Checklist of Immediate Actions for Addressing COVID-19 as Part of Evacuation Planning

Stephen Wong, Jacquelyn Broader, Susan Shaheen
2020

Well planned and coordinated evacuations are critical to saving lives during natural disasters (e.g., hurricanes, wildfires) and human-caused disasters (e.g., chemical spills, terrorism). To complicate matters, recent wildfires in the western United States (U.S.) and multiple hurricanes in the Gulf Coast have coincided with the novel coronavirus (COVID-19) pandemic. As of mid-October 2020, the COVID-19 pandemic has led to over 7.9 million positive cases and over 217,000 deaths in the U.S. alone. Stay-at-home orders and social distancing measures that were introduced to address COVID-...

Experts Stress Teamwork in Response to Natural Disasters

August 27, 2020

An truck and road sign lay by the side of the road after a storm

Transporation Sustainability Reseach Center's Stephen Wong quoted in a Transport Topics article on disaster response. The article discusses different strategies for disaster response, particularly in light of Hurricane Laura, a Category 4 storm, making landfall in August 2020.

Read the full article...

Can Sharing Economy Platforms Increase Social Equity for Vulnerable Populations in Disaster Response and Relief? A Case Study of the 2017 and 2018 California Wildfires

Stephen Wong, Jacquelyn Broader, Susan Shaheen
2020

Ensuring social equity in evacuations and disasters remains a critical challenge for many emergency management and transportation agencies. Recent sharing economy advances – including transportation network companies (TNCs, also known as ridehailing and ridesourcing), carsharing, and homesharing – may supplement public resources and ensure more equitable evacuations. To explore the social equity implications of the sharing economy in disasters, we conducted four focus groups (n=37) of vulnerable populations impacted by California wildfires in 2017 or 2018. To structure these data, we...

A Revealed Preference Methodology to Evaluate Regret Minimization with Challenging Choice Sets: A Wildfire Evacuation Case Study

Stephen Wong, Caspar Chorus, Susan Shaheen, and Joan Walker
2020

Regret is often experienced for difficult, important, and accountable choices. Consequently, we hypothesize that random regret minimization (RRM) may better describe evacuation behavior than traditional random utility maximization (RUM). However, in many travel related contexts, such as evacuation departure timing, specifying choice sets can be challenging due to unknown attribute levels and near-endless alternatives, for example. This has implications especially for estimating RRM models, which calculates attribute-level regret via pairwise comparison of attributes across all...

Bridging the Gap Between Evacuations and the Sharing Economy

Stephen Wong, Joan Walker, and Susan Shaheen
2020

This paper examines the opportunities for addressing evacuations by leveraging the sharing economy. To support this research, we use a mixed-method approach employing archival research of sharing economy actions, 24 high-ranking expert interviews, and a survey of individuals impacted by Hurricane Irma in 2017 (n=645). Using these data, we contribute to the literature in four key ways. First, we summarize sharing economy company actions in 30 U.S. disasters. Second, we discuss results from 24 expert interviews on 11 sharing economy benefits (ranging from resource redundancy to...

Fleeing from Hurricane Irma: Empirical Analysis of Evacuation Behavior Using Discrete Choice Theory

Stephen Wong, Adam Pel, Susan Shaheen, and Caspar Chorus
2020

This paper analyzes the observed decision-making behavior of a sample of individuals impacted by Hurricane Irma in 2017 (n = 645) by applying advanced methods based in discrete choice theory. Our first contribution is identifying population segments with distinct behavior by constructing a latent class choice model for the choice whether to evacuate or not. We find two latent segments distinguished by demographics and risk perception that tend to be either evacuation-keen or evacuation-reluctant and respond differently to mandatory evacuation orders.

Evacuees subsequently face a...

Review of California Wildfire Evacuations from 2017 to 2019

Stephen Wong, Jacquelyn Broader, Susan Shaheen, PhD
2020

Report coverpage

Between 2017 and 2019, California experienced a series of devastating wildfires that together led over one million people to be ordered to evacuate. Due to the speed of many of these wildfires, residents across California found themselves in challenging evacuation situations, often at night and with little time to escape. These evacuations placed considerable stress on public resources and...