Abstract
This paper analyses some environmental and health impacts from the PierPASS program, which shifted drayage trucks operations from daytime/peak hours to evening/night hours to reduce congestion and air pollution at the San Pedro Bay Ports (i.e. the Ports of Los Angeles and Long Beach in Southern California). The authors focus on emissions of nitrogen dioxide (NO2) and particulate matter (PM2.5), and some related health impacts, using a framework that integrates microscopic traffic simulation with emission estimation, air dispersion, and a health impact assessment. The authors find that PierPASS had little impact on traffic congestion and slightly decreased overall emissions of NO2 and PM2.5. However, PierPASS substantially changed their day-night distributions: at night, total port truck emissions increased by 19.4% for NO2 and by 19.5% for PM2.5, while daytime emissions decreased respectively by 5.0% and 4.9%. As a result, PierPASS increased air pollutant concentrations during both daytime and nighttime because of atmospheric boundary layer effects. Finally, health impact analyses using the Environmental Protection Agency’s (EPAâ??s) BenMAP model show that the implementation of PierPASS increased annual health costs in the study area (which does not include the ports themselves) by over $430 million.