Evacuation Decision Making and Behavioral Responses: Individual and Household Nicole Dash 1 and Hugh Gladwin 2 Abstract: Researchers have examined a wide range of factors that affect evacuation decisions after people hear hurricane forecasts and other information. This review of the literature focuses on three broad areas of research that often overlap: warning, risk perception, and evacuation research. Whereas it is challenging to demarcate the literature along these lines, we believe each of these areas represents important dimensions of evacuation decision making. The literature on warning focuses to varying degrees on warning as a social process, rather than a simple result of hearing official warnings. Warnings by themselves do not motivate evacuation—people must perceive risk. The extensive literature on objective and subjective processes in risk perception has to be evaluated. The review concludes with a focus on some important work in modeling evacuation and evacuation decision-making. Finally, we present recommendations for future research that draws on the strength of earlier work while focusing more directly on risk, the information included in hurricane forecasts, and the timing of those forecasts. DOI: 10.1061/ASCE1527-698820078:369 CE Database subject headings: Evacuation; Human factors; Hurricanes; Risk management; Decision making. Introduction Over the last few decades, considerable research has focused on a range of issues related to hurricane evacuation. These issues in- cluded understanding how people interpret warning messages, how they interpret risk, and what types of protective action they take as a result. The body of literature in the area is voluminous, with significant findings that have shaped the process of evacuat- ing at risk populations in the United States when tropical weather systems threaten coastal areas. In this paper we briefly review this elaborate and significant history while highlighting important di- mensions of evacuation decision making by discussing warning research, risk perception, and research focuses specifically on evacuation see the following for more extensive reviews: Drabek 1986; Tierney et al. 2001; Sorenson and Vogt-Sorenson 2006. Specifically, we discuss what is known about warnings, their characteristics and the importance of viewing them as a social process, the balance of objective and subjective processes in risk perception, and finally we examine actual evacuation behavior with a focus on evacuation modeling and social context. In the current age of increasing threats due to tropical weather, the paper concludes with suggestions for future research. While there has been some belief that we have exhausted research in this area, events such as Hurricane Katrina in New Orleans 2005 and Hurricane Rita in the Houston area 2005 suggest the need for a reexamination of paradigms in light of the evolving social world. Warning Before research centered specifically on understanding evacuation itself, the focus tended to be on warnings in general and the warning process more specifically. This section of the paper briefly summarizes some of the significant literature on warning as an integral component of evacuation decision making. Whether official forecasts from the National Hurricane Center, advisories from local and national news media, or information gathered from a variety of online sources, warnings trigger the evacuation decision-making process, and understanding how research in this area evolved helps conceptualize the direction future research should take. Understanding who evacuates and who does not has been one of the cornerstones of research on the preimpact phase of both natural and technological hazards. Warning message characteris- tics, such as its content, source, and frequency, have been an important focus of research Drabek 1986, p. 74. These early attempts at understanding evacuation or other protective mea- sures focused on the warning itself and its belief as key to un- derstanding protective action such as evacuation. The more specific, and less vague the warning, the more likely adaptive response occurs Mileti et al. 1975. If warnings were heard and ultimately believed, then evacuation would be the end result. An alternate approach focused on warning response seeks to understand what characteristics of a warning most effectively trig- ger action. Understanding this perspective would assist in rethink- ing evacuation issues and is a vital component in modeling how individuals process warnings in order to effectively predict behav- ior. Mileti and O’Brien 1992, p. 42 summarize public perception and response to warning as follows: “Public response to commu- nicated risk information is a direct consequence of perceived risk understanding, belief and personalization, the warning informa- 1 Assistant Professor, Dept. of Sociology, Univ. of North Texas, P.O. Box 311157, Denton, TX 76205. E-mail: dash@unt.edu 2 Director, Institute for Public Opinion Research, Florida International Univ., Room HM 246 BBC, 3000 NE 151 St., North Miami, FL 33181. E-mail: gladwin@fiu.edu Note. Discussion open until January 1, 2008. Separate discussions must be submitted for individual papers. To extend the closing date by one month, a written request must be filed with the ASCE Managing Editor. The manuscript for this paper was submitted for review and pos- sible publication on August 4, 2006; approved on March 14, 2007. This paper is part of the Natural Hazards Review, Vol. 8, No. 3, August 1, 2007. ©ASCE, ISSN 1527-6988/2007/3-69–77/$25.00. NATURAL HAZARDS REVIEW © ASCE / AUGUST 2007 / 69 Downloaded 19 Mar 2010 to 130.160.120.56. Redistribution subject to ASCE license or copyright; see http://pubs.asce.org/copyright