MI TI GATI NG DI ESEL TRUCK I MPACTS I N ENVI RONMENTAL JUSTI CE COMMUNI TI ES: TRANSPORTATI ON PLANNI NG AND AI R QUALI TY I N BARRI O LOGAN, SAN DI EGO Contract AQ-04-01: Developing Effective and Quantifiable Air Quality Mitigation Measures November 30, 2008 By Alex Karner Douglas Eisinger, PhD Song Bai, PhD Deb Niemeier, PhD, PE Abstract Background: Barrio Logan is a neighborhood of San Diego, California and is recognized by government agencies as an ‘environmental justice’ community. This work describes a series of sequentially implemented policies to mitigate local diesel truck impacts resulting from goods movement activity at two port facilities while simultaneously improving traffic operations in the communities of Barrio Logan, San Diego and Old Town, National City, both low-income communities of color. Methods: Based on telephone and in-person interviews with key stakeholders, this work provides the first comprehensive documentation of the unique process and solutions which led to traffic operational improvements designed to mitigate local impacts originating from diesel trucks. The study fills the gap in knowledge by performing a local-scale analysis of diesel particulate matter (DPM) emissions in Barrio Logan. Results: Local impacts in Barrio Logan comprised air pollution, noise, and decreased pedestrian safety, while traffic operations in both communities were affected by congestion on the main freeway access, interchanges with insufficient capacity, and heavily mixed land uses both within and adjacent to the communities. These issues provided the impetus for the mitigation effort whose final implementation involved a permanent rerouting of all trucks over five tons to roads external to the community. The results show that while the mitigation did not result in improved regional air quality, it did significantly improve local air quality in the primary affected corridor, resulting in a 99% reduction in DPM emissions, and an 87% reduction in diesel truck vehicle miles traveled.