Adapt to Mitigate: Evaluating Climate Adaptation Strategies for the Chicago Transit Authority

摘要

This report describes ongoing efforts of the Chicago Transit Authority (CTA) to increase resilience of its infrastructure, operations, and ridership to observed and projected impacts of climate change. The Federal Transit Administration (FTA) selected the CTA as one of seven FTA-funded climate adaptation pilots, which are intended to assess the vulnerability of transit agency assets and operations to prolonged heat and intense precipitation, and to develop initial adaptation strategies consistent with agency operating environments. This study focuses on detailed adaptation strategies developed for three CTA system areas: right-of-way flooding, rail heat kinks, and signal house overheating. A life-cycle cost analysis (LCCA) was applied to each of the three issues to compare infrastructure investment costs (i.e. build scenarios) against the costs of no action (i.e. no-build scenarios). In addition, a series of model runs was conducted for each of the three areas to determine the range of outputs relative to various input assumptions, such as event frequency, capital costs, and passenger value of time. The LCCA model was developed to investigate system case studies and provide flexibility for future modification. The study builds upon existing research on projected climate change impacts under the Chicago Climate Action Plan. CTA intends to use this study to inform CTA capital and operating decisions and to offer best practices for regional, national, and international agencies. Crucially, adaptation measures will allow CTA and peer transit agencies to sustain transit ridership, and thus reduce emissions to help create a more stable climate throughout the 21st century.