Improving Shadow Evacuation Management: Case Study of the Graniteville, South Carolina, Chlorine Spill

Facilitating evacuations is a primary aim of disaster management. While under-response to evacuation orders is a typical problem, over-response, or a shadow evacuation, also poses serious problems and should be minimized when possible. This case study of a chlorine spill was designed to evaluate the differences in evacuation behavior between those faced with an evacuation order versus spontaneous, voluntary evacuees. We found that a significant shadow evacuation developed, and we believe that the addition of geographic specificity to the warning message may have limited the scope of the over-response.