SUMMARY – RESEARCH PROJECT 1: Transportation, Health, and Equity: A Community-Centered Study of Road Pricing in Washington, D.C. On-road vehicle emissions are the top contributor to air pollution-related health burdens in Washington, District of Columbia, where they are associated with over 50% of NO2-attributable asthma cases and 23% of air pollution-attributable premature deaths. As in other cities, these health burdens are inequitably distributed largely due to historical and ongoing racially discriminatory planning: PM2.5-attributable morbidity and mortality are five times higher in most impacted areas than in the least impacted areas. District leaders are pursuing policies to address these issues. Road pricing (alternatively called congestion pricing) is a climate change mitigation strategy being considered in cities around the world as a way to lower greenhouse gas emissions from the transportation sector, improve air quality, reduce congestion and commuting times, shift travel from vehicles to public transit and other active transport modes, and improve transportation equity. These policies will likely achieve their intended goals along and near the targeted roads, for example, but it remains unclear whether there will be unintended consequences such as displacing emissions, air quality impacts, and adverse health outcomes outside of the regulated zone. The primary objective of this study is to quantify health and equity implications associated with road pricing schemes under consideration in the Washington, District of Columbia, area. Our aims are to: (1) Identify road pricing strategies to achieve GHG emissions reduction targets in the District by leveraging community collaborator input; (2) Quantify neighborhood-level NO2, PM2.5, and O3 exposure and health effect changes from road pricing through the development of a novel model framework integrating fine-scale transportation modeling, air quality modeling, and population health data; and (3) Assess the equity implications of the proposed road pricing strategies by comparing NO2, PM2.5, and O3 exposure and attributable morbidity and mortality for different population subgroups using spatially-resolved demographic data and race- and ethnicity-specific relative risk estimates. This study will quantify traffic, air quality, health, and environmental justice benefits anticipated from road pricing in the District. The primary significance of this project over existing literature is estimating health and equity benefits of proposed road pricing schemes using fine scale, state-of-the-science transportation, air quality, and health outcomes models. This significance builds directly from the REACH Center theme of using big data to explore climate solutions that advance health and environmental justice, by leveraging the power of novel geospatial datasets and research co-generation with governmental and non-governmental partners. Critically, we have developed the research plan through community and scientific collaborations, and the results will enable future efforts to quantify health and equity implications of proposed policies in the District. Our work will provide a framework to employ fine-scale transportation, air quality, and population data to assess transportation policy schemes seeking to lower GHG and TRAP emissions, improve health, and reduce environmental inequalities.