This report documents the economic impact analysis undertaken by WSDOT’s Freight Systems Division in response to the storm-related closures of I-5 and I-90 in the winter 2007-2008. The closures were the result of severe weather that overwhelmed the roadways and disrupted freight and passenger movements across the state and the West Coast. In all, the highways were closed for eight days, four days for I-5 and four days for I-90. In an effort to obtain a more complete picture of the statewide economic impacts of the highway closures than is typically available through traditional economic impact assessment methods, WSDOT contracted with Washington State University’s Social and Economic Sciences Research Center (SESRC) to conduct survey research and economic analysis of the two storm-related events. WSDOT staff and SESRC researchers worked together to design and develop a new economic assessment methodology that would provide the state’s citizens and decision-makers with a reality-based, comprehensive analysis of the effects of the closures on the state’s freight industry and economy as a whole.