Risks Resulting from Evacuation Include:

If not completed quickly enough, evacuation could cause the evacuees to be exposed to the hazard. For example, if evacuees do not move from their homes fast enough, they could be overcome by an approaching chemical plume.
Risks arise as a result of the mode of transportation chosen by the evacuees. For example, if they choose to evacuate by automobile, they could run out of fuel, experience a mechanical malfunction, or be involved in a motor vehicle crash (MVC). Any of these could effectively stop the evacuation for the affected people, and possibly cause traffic delays that could slow or stop the evacuation for others.