A Study of the Impact of Nine Transportation Management Projects on Hurricane Evacuation Preparedness
In the US, hurricanes are an annual threat to the eastern and gulf coastal states. The 30 costliest and deadliest hurricanes that occurred between 1900 and 2000 resulted in $132 billion in damage and a cumulative number of deaths of almost 15,000. The average expected cost of a hurricane today is about $14 billion.
One method to reduce deaths and costs caused by hurricanes is to evacuate those areas that might be impacted. The importance of this approach has grown with recent advances in the ability of forecasters to more accurately predict the track of a hurricane, thus reducing the number of unnecessary evacuations. However, hurricane evacuations remain difficult transportation activities to manage.
By the time Hurricane Floyd reached landfall in North Carolina in 1999, roughly 3 million people evacuated from a 4-state area. This large-scale evacuation resulted in traffic jams across the regions as motorists flooded the highways. For example, travel time between Charleston and Columbia, South Carolina, normally only 2-1/2 hours, increased to almost 18 hours during the peak period.
In May 2002, FHWA funded grants to nine southeastern states (Texas, Louisiana, Mississippi, Alabama, Florida, Georgia, South Carolina, North Carolina, and Virginia) to improve transportation operations as part of their emergency management program for hurricane evacuations.
Subsequently, a lessons learned document was prepared based on the activities pursued using the federal grants.
The breakdown in the effectiveness of the transportation system during a hurricane evacuation has spurred a renewed interest in evacuation planning both within individual states and at the Federal level. Many states recognized the advantages of using lane reversals (or contraflow) to facilitate evacuations. Learning from past experiences, traffic and emergency management officials have endeavored to modify their evacuation plans to better support highway lane reversals in the future. State emergency management officials also took steps to improve coordination of evacuation and evacuation planning activities between states, monitor and control the transportation infrastructure during evacuations, and disseminate information to the public.
Effectively communicating plans for implementing contraflow lanes during a hurricane evacuation can be very challenging. Several states supported activities to improve agency communications and public information and the following observations were made.
- Coordinate plans across state lines: Plans for an evacuation of New Orleans, LA call for contraflow on I-59 leading north into Mississippi. In order to prevent a bottleneck from occurring at the Mississippi state line, contraflow operation would have to continue into Mississippi. These plans created considerable controversy in Mississippi because the substantial manpower requirements of establishing contraflow on I-59 in Mississippi would diminish the manpower pool available to provide services to Mississippi residents.
A second concern was related to the costs of implementing contraflow in Mississippi. If Mississippi implements contraflow on I-59 as a result of a Louisiana contraflow evacuation decision, but the hurricane changes course or weakens, Federal funds may not be available to reimburse Mississippi for the costs of supporting the Louisiana evacuation. In this case, the State of Mississippi may be left paying part of the cost of a Louisiana evacuation. Based on these concerns in October 2002, Mississippi rescinded its contraflow plans for I-59.
Continued talks between Mississippi and Louisiana officials eventually resulted in a revised agreement in June 2003 for contraflow on I-59 in Mississippi to occur if Louisiana implements a contraflow plan on I-59 in Louisiana.
- Share information: In 2003, Mississippi supported a conference on emergency management practices called the EmTech.Com Symposium, and representatives from multiple state and Federal agencies attended. During this symposium, participants discussed their emergency management practices and how to improve them and set targets for improving coordination and cooperation in the future. At the end of the symposium, participant questionnaires indicated that:
- 75 percent agreed that coordination meetings were extremely important to their organization, with the remaining 25% indicating these meetings were very important.
- 100 percent of participants felt that having similar conferences in the future was extremely important.
The consensus among participants was that meetings helping to coordinate across state and agency boundaries were very important.
- Educate the public about contraflow: The public can slow traffic flow during contraflow situations in many ways, many of which are related to the public’s uncertainty in what they are expected to do during contraflow. Several states used their grant monies to implement public education programs for their state. For example, the Georgia Department of Transportation (GDOT) expanded their traveler information and their traveler assistance programs during evacuations. They used portable Highway Advisory Radio (HAR); variable message signs (VMS); instituted cooperative agreements with public radio stations; and increased the services of the Highway Emergency Response Operator (HERO) incident response vehicles. However, these resources were not very effective to the public since they were not aware of the resources and how to use them; so GDOT implemented a public education campaign creating maps, posters and information sheets.
- Alabama also used the grant money for educating the public, but went a different direction. The Alabama Department of Transportation (ALDOT) used their monies to evaluate methods of disseminating information and, as a result, they began using reversed direction signing, VMS, and Alabama Emergency Radio. They also funded permanent HAR units with quick disconnect antennas, and advanced notification signage at the entrance and exit of the contraflow route.
Most state emergency management officials recognize that providing contraflow is a very effective way to evacuate an area during a hurricane. However, understanding how the reversed roadways should function is essential for achieving acceptable levels of performance. Sharing information and coordinating with adjacent states at the agency level is vital to the success of an evacuation using contraflow lanes, as is educating the public to understand what is expected of them. The examples show that several ITS-enabled strategies, such as reversed roads and HAR, have been implemented along the affected routes; however, experience has shown that little improvement in traffic flow results if the public hasn't been properly informed in advance on how to use these resources. Safety and mobility of the contraflow lanes are goals to be achieved on the roadways during an evacuation.