Evaluation of Heavy- and Medium-Duty On-Road Vehicle Emissions in California's South Coast Air Basin
Publication Date
2018
Document Type
Article
Organizational Units
Chemistry and Biochemistry
Keywords
Atmospheric chemistry, Emissions, Pollutants, Heavy-duty diesel trucks
Abstract
Emission measurements were collected from heavy-duty (HDVs) and medium-duty vehicles (MDVs) at the Peralta weigh station long-term measurement site near Anaheim, CA in 2017. Two Fuel Efficiency Automobile Test units sampled elevated and ground-level exhaust vehicles totaling 2,315 measurements. HDVs (1844 measurements) exhibited historical reductions in fuel specific oxides of nitrogen (NOx) from the 2008 measurements (55%) with increased use of exhaust gas recirculation and selective catalytic reduction systems. However, as these technologies have aged, the in-use benefits have declined. Infrared %opacity measurements of tailpipe soot decreased 14% since 2012 with increased diesel particulate filter (DPF) use, DPF longevity and fleet turnover. 63% of the HDV fleet in 2017 was chassis model year 2011+ compared to only 12% in 2012. The observed MDV fleet (471 measurements) was 1.4 years older than the HDV fleet with average NOx 14% higher. A significant reduction in MDV NOx occurred approximately 2 model years prior to similar HDV reductions (2014 versus 2016 chassis model year). MDV chassis model years 2014+ were able to meet their corresponding NOx laboratory certification standards in-use, whereas HDVs remain slightly above this threshold. Similar MDV NOx emission trends were also observed in data previously collected in Chicago, IL.
Copyright Statement / License for Reuse
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License
Publication Statement
This is an Accepted Manuscript for
Haugen, M. J.; Bishop, G. A.; Thiruvengadam, A.; Carder, D. K. (2018) Evaluation of Heavy- and Medium-Duty On-Road Vehicle Emissions in California's South Coast Air Basin. Environ. Sci. Technol., 52(22), 13298-13305. DOI: 10.1021/acs.est.8b03994.
Copyright held by the American Chemical Society. User is responsible for all copyright compliance.
Rights Holder
Molly J. Haugen, Gary A. Bishop, Arvind Thiruvengadam, Daniel K. Carder
Provenance
Received from author
File Format
application/pdf
Language
English (eng)
Extent
38 pgs
File Size
586 KB
Recommended Citation
Haugen, M. J.; Bishop, G. A.; Thiruvengadam, A.; Carder, D. K. (2018) Evaluation of Heavy- and Medium-Duty On-Road Vehicle Emissions in California's South Coast Air Basin. Environ. Sci. Technol., 52(22), 13298-13305. DOI: 10.1021/acs.est.8b03994.
DOI Link
https://doi.org/10.1021/acs.est.8b03994