Evaluation of Hurricane Evacuation Order Plans: Hurricane Florence Case Study.

This paper introduces an approach to evaluate the performance of a previously implemented or proposed hurricane evacuation plan that describes where and when official evacuation orders are issued. The approach involves use of the new integrated scenario-based evacuation (ISE) decision support tool to define a best track evacuation plan as a reference point and measure the performance of other plans in relation to that according to their ability to meet multiple stated objectives: minimizing risk to the population, travel time, and time people are away from their homes. Using North Carolina in Hurricane Florence (2018) as a case study, we demonstrate the process by evaluating performance of both the actual set of orders as executed and the orders that would have been recommended if the new ISE decision support tool had been used during the event. All three plans were evaluated for two cases—assuming the hurricane unfolds as it actually did, and if the hurricane had instead evolved like one of 21 other realistic scenarios. Results suggest the actual evacuation was quite good, and the ISE tool could have resulted in improved evacuation performance. This paper introduces a comprehensive, replicable approach to evaluating the performance of a previously implemented or proposed hurricane evacuation plan (i.e., a plan that describes where and when official evacuation orders are issued). Currently, there is no formal way to do so. The method presented defines as a reference point the evacuation plan that would minimize the stated aims if there was no uncertainty in the hurricane behavior, that is, if we had a crystal ball so that at the time the hurricane formed we could know the eventual track, intensity, and associated wind, rain, and flooding hazards exactly. The approach then measures the performance of other plans in relation to that reference, with performance based on their ability to meet multiple objectives: minimizing risk to the population, travel time, and time people are away from their homes. This new method can be of practical use to (1) provide after-the-fact evaluation of past evacuations to facilitate learning, (2) support planning through comparison of alternative strategies and decision support tools for hypothetical future hurricanes, and (3) gauge expectations about what performance can be reasonably expected in different circumstances. [ABSTRACT FROM AUTHOR]