Near-Road Air Quality: Insights from a U.S. DOT Five-Year Transportation Pooled Fund Study

Research shows that substantial traffic, especially diesel-powered trucks and buses, can create pollution hot spots within a few hundred meters of major roads. In recognition of the importance of addressing near-road air pollution, eight state and federal agencies pooled their research efforts on the topic, obtaining and evaluating an unprecedented amount of near-road air quality data. From 2014 through 2019, the agencies formed the Near-Road Air Quality Transportation Pooled Fund (TPF-5(284)), sponsored by the U.S. Department of Transportation (DOT), and selected Sonoma Technology, Inc., to provide planning and research support. This article highlights the research findings including: (1) carbon monoxide (CO) is no longer a near-road problem, new vehicles emit a tiny fraction of the CO emitted by similar vehicles built decades ago; (2) virtually all near-road nitrogen dioxide (NO₂) concentrations fell below existing health-based air quality standards; and (3) most areas have small particulate matter (PM₂.₅) concentrations below National Ambient Air Quality Standards (NAAQS), and emission trends suggest that future conditions will continue to improve. Additional findings discussed in this article cover air pollution differences between near-road and surrounding areas or background concentration; fleet turnover projections and resulting forecasted PM₂.₅ exhaust emissions; and real-world air quality measurements compared to AERMOD modeled concentrations.


  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; Photos; Tables;
  • Pagination: pp 20-27
  • Serial:
    • TR News
    • Issue Number: 332
    • Publisher: Transportation Research Board
    • ISSN: 0738-6826

Subject/Index Terms

Filing Info

  • Accession Number: 01773684
  • Record Type: Publication
  • Files: TRIS, TRB, ATRI
  • Created Date: Jun 3 2021 9:21AM