Quantifying and Analyzing the Costs of Climate Change on Local Transportation Infrastructure: A Case Study from Portland, Oregon

Climate change has the potential to produce more frequent and intense rainfall events. In the Portland metropolitan area these events have the potential to flood several urban bridges and streets. This research aims to quantify and analyze the impacts of urban flooding on transportation at the local level. Cost data relevant to a typical flooding event for two urban watersheds were collected and analyzed. The economic costs of flooding were classified and quantified based on available historical data and the cost of potential delays. Results indicate that any cost analysis is extremely sensitive to the occurrence of human fatalities or injuries and fairly insensitive to delay costs. In addition, this research presents a comprehensive classification of flooding costs, identifies preventative measures and data collection needs, and makes short- and long-term recommendations.