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. Two states, Louisiana and North Carolina, used federal grants to deploy traffic monitoring devices on hurricane evacuation routes. In both cases, the states combined the deployment of these devices with other projects or programs to reduce costs and improve performance.
The Louisiana Department of Transportation and Development (LA DOTD) collaborated with the United States Geological Survey (USGS) to develop and deploy Information Stations that provide real-time access to both hydrographic and traffic data. In North Carolina, two separately funded projects were brought together to enable deployment of more traffic monitoring stations than originally planned. The following discussion focuses on cost effective approaches to providing real-time traffic data for use during hurricane evacuations.
- Leverage the USGS streamgaging programming: Louisiana began working with the USGS to obtain real-time warnings when stream height measurements approached levels that would flood State routes. During this process, Louisiana discovered that the streamgaging field devices used by USGS had extra ports available for collecting additional data and that LA DOTD might be able to connect traffic count instrumentation to these ports. This would allow LA DOTD to collect near real-time traffic data from locations across the state without the need to deploy a communications network for transmitting these data. Instead, the traffic data would be communicated via satellite to the USGS data processing centers, and LA DOTD could pull the data from that center over the Internet.
- As it turned out, the Louisiana Office of Emergency Planning (LOEP) was interested in deploying new streamgages for detecting floods. A 3-way collaboration between LA DOTD, LOEP, and USGS was formed to develop and deploy Information Stations that would provide near real-time access to both hydrographic and traffic data. LA DOTD developed traffic count instruments that were compatible with the USGS streamgaging equipment, and stations were successfully deployed at seven test sites.
- Coordinate the deployments of synergistic programs: North Carolina attempted to fund a project to provide real-time traffic information along the contraflow portion of I-40. When an attempt to secure a contractor to deploy the field traffic monitoring stations and the communications network with the available FHWA grant was unsuccessful, they chose to supplement the grant with funding available from another project. This enabled the department to provide traveler information improvements on I-95 and I-40 in Johnston County, where the end of the I-40 contraflow was planned. Because the traveler information project included installing much of the infrastructure and software needed to communicate and display traffic information, the grant funding was focused on purchasing additional traffic monitoring stations for deployment at locations key for monitoring evacuations. By integrating the evacuation support activities with another ITS program, North Carolina leveraged the communications and software interface elements of the other program to help provide real-time traffic information during hurricane evacuations.
This lesson documents that agencies should make an effort to identify other projects or programs inside or outside their agency where partnering would be beneficial to all parties involved. For transportation departments to implement ITS components, especially in remote locations, the costs to provide the power and communications infrastructure needed to make the data readily accessible can be substantial. Sharing capital, operations, and maintenance costs can be beneficial to all the agencies involved. In the examples provided, two agencies in Louisiana were able to work together with the USGS to deploy Information Stations that included both hydrographic and traffic data, and North Carolina was able to combine two separately funded projects and deploy additional traffic monitoring stations at key locations to monitor evacuations. Agencies can realize a significant impact by providing cost-effective solutions to deploying ITS components in remote locations. Deploying traffic monitoring stations on key routes will provide transportation departments with the data they need to improve the safety and mobility of evacuees during a hurricane evacuation.