Determinants of Residents’ Shadow Evacuation Intention During a Hurricane in the Rio Grande Valley, Texas

Studies on hurricane evacuation behaviour focus primarily on why individuals do not evacuate when they are instructed to, while few examine the reasons why individuals choose to evacuate under conditions that would not require them to, termed shadow evacuation. Such behaviour might delay the timely evacuation of more at-risk coastal residents. To better understand the reasons for shadow evacuation, this study analyzes data from a household evacuation behavioural survey administered between 2012-2013 to 479 households in Cameron, Hidalgo, and Willacy Counties, Texas, known as the Rio Grande Valley. This area features a number of Colonia neighborhoods with high rates of shadow evacuation in previous hurricanes. The analyses describe and regress shadow evacuation intention by risk perceptions, information reliance, preparedness level, previous experience, and selected geographic, social, and demographic characteristics. Results of the analysis show that residents in colonias had a slightly higher rate of shadow evacuation intention (OR = 1.28) than those from urban areas. The ORs varied in some risk areas along with the impacts of gender, race, and language preference. A follow-up regression analysis reveals that previous hurricane experience, risk perception, and preparedness level could effectively mitigate residents’ shadow evacuation behaviour. The findings of this study suggest opportunities for how local authorities can better understand the causes of shadow evacuation and strengthen hurricane evacuation planning, risk communication, and public education efforts to curb unnecessary evacuation