Queueing-driven transportation emissions at international ports of entry create localized air pollution hotspots affecting commuters, pedestrians, and facility workers. This study examines the Bridge of the Americas, a U.S.-Mexico port of entry in El Paso, Texas, using continuous Federal Equivalent Method monitoring and AERMOD dispersion modeling to assess traffic-related air pollutants. Monitored PM 2.5 and NO 2 concentrations were elevated at the port compared to a nearby reference site. Modeling showed that concentrations plateau once vehicle queues exceed 270 meters, with levels declining tenfold within 200 meters of the traffic lanes. Pedestrians experienced 75% of in-lane pollutant concentrations, and toll booth workers 66%. Modeled contributions accounted for 51% of PM 2.5 , 147% of PM 10 , and 7% of NO 2 relative to monitored averages. Findings demonstrate how queue length, traffic mix, and weather impact exposure and support strategies, such as queue management, lane design, and walkway placement, to reduce emissions at border crossings. • Pollution peaks when idling queues exceed 270 meters from toll booths • Concentrations drop tenfold within 200-meter horizontal distance of traffic lanes • Pedestrians face 75 percent of in-lane modeled pollutants, toll workers 66 percent • BOTA modeled emissions account for 51 percent of PM 2.5 and 147 percent of PM 10 • Integrated monitoring and modeling framework informs mitigation strategies
Chavez et al. (Wed,) studied this question.