Disruptive events caused by weather and climate extremes are imposing significant and rising costs on transportation agencies in the United States. These events – ranging from dust storms to landslides to floods – adversely impact transportation system infrastructure integrity, reliability, level of service, and user safety. Increasingly, severe weather events are altering the priorities and staffing patterns of state Departments of Transportation (DOTs) as these agencies take on larger emergency response and management responsibilities. The burden of preparing for and recovering from extreme weather events can strain the financial and human resources of transportation agencies at all levels and the indirect costs associated with longer travel times and reduced level of service impose additional societal costs. The importance of these disruptive events have spurred numerous national agencies and groups to develop a range of resources intended to assist state DOTs and other transportation agencies in developing adaptation strategies to reduce the surface transportation system’s vulnerability to weather and climate extremes.
This white paper reviews the state of the practice and knowledge for climate adaptation processes at state DOTs and local transportation agencies. It also has interviews with stakeholders and reviews of recent literature. Ultimately, gaps in knowledge, methods and data are identified in the context of a simplified framework. We propose that the essence of current frameworks can be simplified into 5 core components: 1) inventorying the assets in the system, 2) assessing climate threats, 3) evaluating vulnerability (given the assets and threats identified in steps one and two), 4) rating the criticality of each asset to overall system performance, and finally 5) implementing adaptation actions to reduce adverse impacts based on the vulnerability and criticality evaluations.