Like manyÂ states on the East Coast, North Carolina faces the threat of hurricanes during the summer months. The current evacuation strategy for the state is a full reversal of I-40, allowing all lanes to travel away from the coast. Although this strategy has never been activated, the North Carolina Department of Transportation (NCDOT) recognized that thereÂ couldÂ beÂ situations in which it may not work. NCDOT hired Kittelson to create a â€œplaybookâ€ that will allow theÂ State to have multiple evacuation strategiesÂ at handÂ andÂ toÂ understandÂ theÂ conditionsÂ that wouldÂ mandate each strategy to be implemented.Â Â
Typically,Â evacuation studiesÂ learn demand byÂ focusingÂ on theÂ numberÂ of people who evacuate overÂ a period of time. However, for this study,Â Kittelson looked at different capacity scenarios by modifyingÂ Freeval, a powerful analysis toolÂ used to look atÂ capacityÂ andÂ monitorÂ signalized intersections over multiple days. The team also took existing tools and strategies from NCDOT andÂ adapted them intoÂ FreevalÂ to get a better understandingÂ ofÂ capacity, speeds, and travel time. This allowed the teamÂ to seeÂ what could happen during each evacuation strategyÂ and how that strategy mightÂ affect traffic. Kittelson met with allÂ NCDOT divisions andÂ Cities along the coast to hear directly about their experiences from past evacuations to inform the process further.Â Â
Creating a Toolbox for North Carolina's Hurricane Evacuation Routes
The study wasÂ completedÂ withinÂ just 4 months toÂ ensure NCDOT would have the toolbox they needed in time for the following hurricane season. Kittelson created an evacuation strategy toolbox that is the first of its kind, giving North CarolinaÂ a resourceÂ forÂ understandingÂ different evacuationÂ strategiesÂ and the situations that call for them.Â NCDOT used the results of the study to prepare more detailed evacuation plans for each of the three corridors, including geometric changes to allow strategies like part time shoulder use or merge extensions.