The Federal Highway Administration (FHWA) began to address the impacts of changing natural hazards near the beginning of the George W. Bush administration. The impacts of extreme weather events, such as more frequent and intense heat waves and flooding, threaten the considerable federal investment in transportation infrastructure. FHWA is partnering with State and local transportation agencies to increase the resilience of the transportation system to these impacts.
Initial Efforts Focused on Impacts of Extreme Weather on Transportation Systems
FHWA's initial efforts focused on understanding the scope and scale of extreme weather impacts on transportation. DOT (with FHWA support) commissioned a series of short papers by researchers across government and convened a conference in 2002. FHWA then led the Gulf Coast Study. Issued in March 2008, the report concluded that many critical transportation assets were extremely vulnerable. For example 19% of major roads and 5% of rail lines in the central Gulf Coast region could be affected if sea levels rise by just 2 feet, a conservative estimate of projected sea level rise in the region over the next 50 to 100 years. Hurricane Katrina further underscored this conclusion. FHWA's Potential Impacts of Global Sea Level Rise on Transportation Infrastructure - Atlantic Coast Study followed in October 2008. The impacts of sea level rise also began to arise as issues on a few highway projects, such as the Bonner Bridge replacement project along the Outer Banks of North Carolina.
From the initial projects, we learned that changing conditions and extreme weather impacts threaten key FHWA goals of safety, system reliability, asset management, and financial stewardship. More frequent heat waves stress materials while heavier rainfall, rising sea levels, and stronger hurricanes cause flooding that damages roadways and disrupts traffic. We also learned that global models were not well suited for making design decisions at the project-level. We needed projections of changing conditions at a fine enough scale to develop effective strategies to adapt to infrastructure at the project and systems levels.
Next Steps: Developed Tools and Information for States to Assess Vulnerabilities
FHWA then embarked on a series of efforts designed to gain experience applying information on changing conditions and to develop capacity in state departments of transportation (DOTs) and metropolitan planning organizations (MPOs) (our main stakeholders).
Recent Efforts Analyze Strategies to Improve Resilience
FHWA's most recent efforts include research to help areas analyze adaptation strategies to increase resiliency. FHWA has conducted engineering analyses of adaptation options such as enlarging culverts, raising bridges, or using more heat resistant materials as part of three projects discussed below.
Integrating Resilience into FHWA Programs
FHWA is integrating resilience considerations into the agency's programs, guidance, and policies, consistent with transportation law1 and policy. FHWA Order 5520 commits the agency to taking action in this area.
The actions outlined above assist FHWA and stakeholders in responsibly managing the risks posed by a changing conditions. Managing these risks is critical to FHWA's core mission to improve highway system performance-particularly its safety, reliability and, effectiveness.
1 Transportation law charges FHWA with extending the useful life of highways, promoting highway safety, and serving as a wise steward of Federal funds (see 23 U.S.C. 109, 116, and 134 among others).
