Human Response to Vertical Shelters “An Experimental Note” *

Abstract

As both coastal population and coastal evacuation times increase, there is a need to consider the vertical evacuation option. This research examines the changes a “vertical shelter” option might introduce in decisions to evacuate. It focuses on two possible human behavior problems associated with the use of “vertical shelters.” Problem one is whether the existence of a “vertical shelter” option will inhibit large numbers of people from evacuating horizontally. Problem two is whether the existence of a “vertical shelter” option will encourage people to delay their decisions to evacuate outside the threatened area.

In order to address these problems two experiments were conducted in Galveston, Texas USA. In each experiment the sample was divided into a control and experimental group. All participants were shown videotapes of Hurricane Alicia. They were then requested to select response options based on written hurricane advisories. Only the experimental group had vertical evacuation as one of the response options. The second experiment also examined the effect of the Galveston Seawall on the responses.

The results of these experiments provide no statistically significant evidence that for the participants the presence of a “vertical shelter” would delay or inhibit them from evacuating horizontally. However, because of the small sample, only large differences could have been detected.