Minimizing Patient Transport Times During Mass Population Evacuations

Emergency evacuation in a health care environment has focused on methods for evacuating a facility, resources for transferring patients, and sufficient capacity at sheltering facilities. What has been overlooked is the interaction between health care facility evacuation and any communitywide evacuation that would result in significant roadway congestion. This paper focuses on how to route hospital vehicles during a hurricane evacuation. To provide an analytical comparison of evacuation time, delay, and routes across various evacuation scenarios, a simulation model is developed that combines hospital and general population traffic. The tailored model incorporates mesoscopic traffic flow concepts to evaluate a region covering several hundred miles with the ability to control speeds and make decisions at the individual vehicle level. With this novel modeling approach, evacuation planners can easily program the routes, test the travel times, and quickly consider different scenarios. It can be a useful tool for hospital evacuation planners and statewide or regional evacuation planners making decisions about traffic operational strategies. The analysis includes consideration of the evacuation of the Charleston, South Carolina, metropolitan area during a hurricane threat. The study found that to evacuate all patients 6 h before a hurricane landfall, the hospital evacuation must start at least 12 h before the mandatory evacuation order (a typical 24-h notice). Alternatively, the hospital evacuation can take place at the same time as the mandatory evacuation if both begin 48 h before landfall.