Emergency Transportation Operations

Highway Evacuations in Selected Metropolitan Areas: Assessment of Impediments

Atlanta, Georgia

#11-Most Congested
#8-Population (5,376,000)
INRIX® National Traffic Scorecard 2009

map of Atlanta, Georgia

The Plan

While localized evacuations occurred in the fall of 2009 due to inundating rain, Georgia's most recent large-scale, mass evacuation occurred in 2004. A chemical fire impacted Rockdale County, to the east of Atlanta. Authorities evacuated approximately 8,000 people, giving instructions based on the direction of the plume. Since then, the State and local jurisdictions have discussed how best to update evacuation plans.

The March 2009 plan provided to FHWA for this study represents the Atlanta Region's most current evacuation plan proposal. This plan assumes a no-notice trigger. Once local plans are updated and the regional plan has more detail, the goal is to incorporate the plan into the State plan. It includes the 10 counties of the Atlanta Regional Commission's (ARC) planning area and 10 of the transportation planning area's 18 counties. The ARC6, one of 12 regional commissions in Georgia and a Metropolitan Planning Organization (MPO), led this planning effort. Several years ago, the Georgia DOT (GDOT) hired a consultant firm to undertake an evacuation study of a 1-mile radius around the State Capitol in downtown Atlanta. The study provided data and input into the Atlanta Regional Evacuation Plan.

The March 2009 plan resulted from an 18-month effort that included transportation staff, public officials, emergency management agency directors, American Red Cross representatives and Georgia Emergency Management Agency (GEMA) staff. The mayor of Atlanta asked the ARC Board to work cooperatively to develop a regional evacuation plan, resulting in the strong support of elected leadership. The GEMA and the Fulton County Emergency Management Agency pooled funds and leveraged DHS grants with ARC transportation funds, using an MPO staff representative to participate on the Planning Advisory Team to develop the plan. The Fayette County manager, a former county Emergency Management Agency director and a former chair of the Area 7 All Hazards Council was a key leader and visionary of regional evacuation planning and participated in the process. The ARC has a strong history of developing multidisciplinary plans as an MPO, an Area Agency on Aging, and other planning responsibilities in the areas of workforce development, regional development planning and water supply planning.

The most recent planning effort used a community-wide workshop concept, drawing more than 100 representatives from all levels of government, the United Way, the American Red Cross and other private and non-profit stakeholders. As a result, the plan emphasizes roles and responsibilities among responders. The Atlanta Regional evacuation plan includes a discussion of mutual aid agreements that arose from post 1996-Olympics legislation, as well as a discussion on how to incorporate the concerns of the special needs population into the plan.

Currently, authorities plan to include the following in the next iteration of the March 2009 plan:

  • local annexes;
  • discussion of database under development to identify special needs populations;
  • updated arterial study;
  • updated discussion on mutual aid and cooperative agreements to address liability weaknesses;
  • section on how to use buses since school buses are not available for 4 hours to enable schools to evacuate school children, alleviating congestion on rural routes caused by parents heading toward schools;
  • information on a traffic clearance tool, which is a database that may be populated with real-time traffic information so the public and authorities can get up-to-date traffic conditions information, and
  • traffic signal coordination.

The next revision will be done within 3 years. The current plan identifies 12 evacuation zones and describes how people should travel out of those zones. Interviewees noted that the revised plan should include local participation to ensure that the localities agree with those evacuation zones. During the next planning cycle, officials will update the regional transportation plan by addressing the next level of detail, specifically at the local government level. The ARC notes that the next Transportation Improvement Plan (TIP) will include activities that support the following goals: promote safety, improve congestion, and integrate public safety and transportation efforts. Also, ARC will incorporate evacuation policy and assumptions into the next update of the 2005 Regional ITS architecture.

The GDOT is currently implementing a coordinated traffic signal project that will allow the Department to actively manage 300-400 traffic signals on certain key, cross-jurisdictional corridors. The corridor identification has not been finalized, but evacuation route designation was not a criterion for selection. It is possible that one or more routes selected by GDOT are designated for primary evacuation purposes. While the primary purpose of the project is to alleviate peak-hour congestion, it could also serve as an improvement for evacuation purposes.

Top Highway Impediments

Top Highway Impediments
ATLANTA

  • Contraflow Constraints
  • Infrastructure Limitations
  • Arterial Road Systems with Overpasses Cannot Accommodate Trailer Heights
  • Bridge Weight Restrictions Impede Movements
  • Traffic Data is Scattered Throughout the Region

The interviewees reported that the following impediments would impact a large-scale, mass evacuation from the Atlanta area:

  1. Contraflow Constraints - Authorities believe that they will not be able to organize and execute a contraflow operation if needed. The current plan assumes that the expressway system will serve as the major evacuation route for cars, but interviewees indicate that they may not be practical for contraflow operations. For this reason, planning must include an emphasis on moving evacuees over arterial roads as well as freeways.
  2. Infrastructure Limitations - Absent a contraflow operations plan, roads may lack sufficient lanes for a mass evacuation event. Also, poor drainage results in flooding and road closures (particularly during hurricane events), and the current designation of NHS routes does not exactly align with strategic evacuation routes.
  3. Arterial Road Systems with Overpasses Cannot Accommodate Trailer Heights - The NHS includes many arterial systems. In Atlanta, NHS arterial roads include overpasses whose design complicates the accommodation of the height of 18 wheelers as well as military equipment moved on flatbeds. This might lead to potential blockages and clearance issues that would impede an evacuation along NHS arterial roads.
  4. Bridge Weight Restrictions Impede Movements - Weight limits on bridges in parts of the Atlanta area would force heavier truck traffic onto NHS roads, increasing congestion on those roads and slowing an evacuation operations.
  5. Traffic Data is Scattered Throughout the Region - There is no single source for mobility performance data in the Metro Atlanta Region. Instead, most local jurisdictions collect, manage, and maintain their own data to address their own local needs. The GDOT Office of Transportation Data maintains a statewide traffic counting program called STARS (State Traffic and Report Statistics), which is Web accessible. STARS includes historic and current traffic count data, and is either updated or estimated on a 2-year cycle (updated 2009 data will be available in mid-2010). As part of the regional Congestion Management Process (CMP), ARC is developing an architecture for maintaining a regional performance data clearinghouse that will allow local jurisdictions, as well as regional planning partners, to upload their data into a single location. The ARC is also exploring ways to encourage planning partners and jurisdictions to collect mobility data that meets certain minimum specifications and parameters (e.g., intersection turning movement counts must include a consecutive 48-hour time period).

The ARC is currently undertaking a Strategic Regional Thoroughfare Plan, which will incorporate assumptions, findings, and recommendations of the 2009 Regional Evacuation Plan to help develop the Regional Thoroughfare Network (TFN) as well as associated policies and guidelines.

Footnotes

6 The Atlanta Regional Commission membership includes chief elected officials of the region and appointed citizen members.

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