A Cluster Analysis on Barriers to Evacuate

Background/Purpose: How do individuals perceive barriers that prevent them from leaving immediately when ordered to evacuate? In this study, a section from a national random-digit dial survey of the American public's opinions and behaviors on preparedness was used to cluster barriers that hinder an individual from evacuating in an emergency. The study aimed the following: (1) how do individuals perceive and cluster these barriers and (2) how do they differ when controlling for region, political ideology, and socioeconomic status.

Methods: Clustering and similarity trees are useful techniques used to group related objects and can be implemented to assess how individuals think of psychological concepts. Ten barriers—children, elderly relative or friend, sick relative or friend, pets, belongings, family or friends, inability to leave without help, lack of confidence in the evacuation order, lack of transportation, and security of their home—were asked and fit using the Extended Similarities Trees clustering method.

Results/Outcomes: Individuals perceived the elderly and the sick together as well as children and family as one entity. Furthermore, transportation and inability to leave without help were grouped, while belongings and security of home were also considered together. However, pets and lack of confidence in the evacuation order were left ungrouped with any other barrier. There were variations by region and socioeconomic factors.

Conclusion: The findings of this study provide insight for policymakers on which barriers to expect in different groups of individuals so that more effective interventions can be designed to enhance planning efforts in disaster situations.