Alternative Methods to Increase the Effectiveness of Freeway Contraflow Evacuation

The city of New Orleans is among the most vulnerable cities in the world to the threat of hurricanes. To protect its population from these storms, officials in Louisiana have joined a growing number of states that are planning to use contraflow freeway operations to expedite the evacuation of threatened areas. Although contraflow is widely regarded as a major advance in evacuation planning and response, no one really knows how well, or even if, it will work. Research was undertaken to improve the understanding of traffic conditions on contraflow freeway segments during an evacuation. The CORSIM microscopic traffic-simulation program was used to model the freeway configuration that will be used to evacuate New Orleans as well as two alternative scenarios for this same segment. The results showed that the currently proposed configuration might result in an underutilization of the contraflow segment, thus significantly limiting the number of evacuees who can get out of the city. The study also showed how the effectiveness of the New Orleans contraflow segment might be significantly improved with some simple and inexpensive modifications to the existing plan. Most important, the results of the research underscore the critical nature of proper planning and design of contraflow entry points and how they are often overlooked for both emergency and nonemergency conditions.