Modeling Impacts of Cold Climates on Vehicle Emissions

Vehicle emissions include carbon monoxide (CO), nitrogen oxides (NOx = NO + NO₂), volatile organic compounds (VOCs), and air toxics such as benzene. Each of these pollutants is linked to adverse human health effects. To evaluate the contributions of start emissions to total vehicle emissions of these pollutants in the U.S. Pacific Northwest, the MOVES2010b emission model was applied to Ada and Canyon counties in Idaho and Yakima County in Washington using county-specific vehicle fleet and activity data for 2012 and January meteorological conditions. MOVES2010b indicates that start emissions dominate total vehicle emission for CO, VOCs, and benzene, and include a significant portion of total vehicle NOx emissions. Depending on the county, vehicle start emissions contribute 68–70%, 22–26%, 65–67%, and 82–83% to total vehicle emissions of CO, NOx, VOC, and benzene, respectively. The MOVES2010b model was also run to generate temperature response curves for vehicle start emissions of CO, NOx, and VOCs. Start emissions of CO, NOx, and VOCs all show a strong dependence on temperature, though the sensitivities differ for different pollutants, vehicle types, vehicle model years, and fuel types. MOVES2010b estimates that when the temperature increases from -10°F to 70°F, start emissions decrease by 9–96%. This study highlights the importance of start emissions in contributing to air pollution due to motor vehicles during winter and the sensitivity of start emissions to temperature. For regions with colder winter climates, such as Montana and Alaska, contributions from start emissions would be even greater. Accurate estimates of vehicle start emissions require accurate models. Experimental measurements of vehicle emissions at a full range of wintertime temperatures should be carried out and compared with the results of this study to systematically evaluate the accuracy of MOVES predictions.

Language

  • English

Media Info

  • Media Type: Digital/other
  • Edition: Final Report
  • Features: Figures; Maps; References; Tables;
  • Pagination: 33p

Subject/Index Terms

Filing Info

  • Accession Number: 01630143
  • Record Type: Publication
  • Report/Paper Numbers: INE/AUTC 17.05
  • Files: NTL, TRIS, ATRI, USDOT
  • Created Date: Feb 22 2017 3:29PM