title: On-road heavy-duty vehicle emissions monitoring system.
abstract: The introduction of particulate and oxides of nitrogen (NOx) after-treatment controls on heavy-duty vehicles has spurred the need for fleet emissions data to monitor their reliability and effectiveness. The University of Denver has developed a new method for rapidly measuring heavy-duty vehicles for gaseous and particulate fuel specific emissions. The method was recently used to collect 3088 measurements at a Port of Los Angeles location and a weigh station on I-5 in northern California. The weigh station NOx emissions for 2014 models are 73% lower than 2010 models (3.8 vs 13.9 gNOx/kg of fuel) and look to continue to decrease with newer models. The Port site has a heavy-duty fleet that has been entirely equipped with diesel particulate filters since 2010. Total particulate mass and black carbon measurements showed that only 3% of the Port vehicles measured exceed expected emission limits with mean gPM/kg of fuel emissions of 0.031 ± 0.007 and mean gBC/kg of fuel emissions of 0.020 ± 0.003. Mean particulate emissions were higher for the older weigh station fleet but 2011 and newer trucks gPM/kg of fuel emissions were nevertheless more than a factor of 30 lower than the means for pre-DPF (2007 and older) model years.
authors.affiliation: Department of Chemistry and Biochemistry, University of Denver , Denver Colorado 80208, United States.
authors.forename: Gary A
authors.initials: GA
authors.lastname: Bishop
authors.forename: Rachel
authors.initials: R
authors.lastname: Hottor-Raguindin
authors.forename: Donald H
authors.initials: DH
authors.lastname: Stedman
authors.forename: Peter
authors.initials: P
authors.lastname: McClintock
authors.forename: Ed
authors.initials: E
authors.lastname: Theobald
authors.forename: Jeremy D
authors.initials: JD
authors.lastname: Johnson
authors.forename: Doh-Won
authors.initials: DW
authors.lastname: Lee
authors.forename: Josias
authors.initials: J
authors.lastname: Zietsman
authors.forename: Chandan
authors.initials: C
authors.lastname: Misra
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D002140:California; D004784:Environmental Monitoring / Q000379:methods*; D015141:Los Angeles; D008962:Models, Theoretical; D018986:Motor Vehicles; D009589:Nitrogen Oxides / Q000032:analysis; D015203:Reproducibility of Results; D053260:Soot; D001335:Vehicle Emissions / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D009589:Nitrogen Oxides; D053260:Soot; D001335:Vehicle Emissions