This document was developed by Federal Highway Administration (FHWA) staff, but it draws heavily from a body of work produced for the FHWA by ICF International. It also draws from experiences and work of the North Jersey Transportation Planning Authority (NJTPA), the Metropolitan Transportation Commission (MTC), the Bay Area Conservation and Development Commission (BCDC), the California Department of Transportation District 4, the Washington State Department of Transportation (WSDOT), the Oahu Metropolitan Planning Organization (OahuMPO), the University of Virginia Center for Transportation Studies, and the many other agencies involved in the FHWA's 2010-2011 Climate Change Vulnerability and Risk Assessment Pilot Program.
The Federal Highway Administration's (FHWA's) Climate Change and Extreme Weather Vulnerability Assessment Framework is a guide for transportation agencies interested in assessing their vulnerability to climate change and extreme weather events. It gives an overview of key steps in conducting vulnerability assessments and uses in-practice examples to demonstrate a variety of ways to gather and process information. The framework is comprised of three key steps: defining study objectives and scope; assessing vulnerability; and incorporating results into decision making.
Defining the objectives and scope of the study at the beginning of the process is important because it creates boundaries for the analysis and can limit extraneous data collection efforts. To define study scope, agencies should first consider their overall goals and objectives. Objectives for a vulnerability assessment may include siting new assets in areas less vulnerable to climate change, educating staff regarding overall climate risks to the agency's transportation system, or informing the development of adaptation strategies. Based on these objectives, an agency can then select and characterize relevant assets and identify climate variables for study. The initial objectives and scope may be altered by the other steps in the process as new information is gathered or limitations are better understood.
Climate change and extreme weather vulnerability in the transportation context are a function of a transportation asset or system's sensitivity to climate effects, exposure to climate effects, and adaptive capacity. Tasks in the vulnerability assessment include: gathering and integrating data and information on asset location, characteristics, and climate sensitivities; gathering and obtaining information on historical weather events and projected climate; combining the asset and climate information to identify vulnerabilities; and potentially, assigning a level of risk of the climate impacts on the assets. The vulnerability assessment work is an iterative process; information gathered on assets may inform climate information needs and vice versa.
Incorporating the results of the vulnerability assessment into the agency's decision-making process ensures that the study results are used in practice. An agency may be able to use the results of the assessment in its asset management programs, hazard mitigation plans, transportation planning project selection criteria, or other programs and processes. In addition, a transportation agency might be interested in using the results of the analysis to inform the development of specific adaptation strategies for assets identified as highly vulnerable to climate change.