MOVES vs. MOBILE6.2: Differences in Emission Factors and Regional Air Quality Predictions

Vehicle emissions play a significant role in urban air quality. Several emission factor models have been developed to estimate the emission rates of different pollutants from a vehicle. The US EPA used MOBILE series to estimate the emissions till 2010 when it was replaced by the Motor Vehicle Emission Simulator (MOVES). In the first part of this study the vehicle fleet averaged emission factors for different pollutants estimated by the MOVES and the MOBILE6.2 models are compared. The most significant differences in emission factors appear at low speed range (less than 20 mph) at which the MOVES model predicts higher concentrations for most species emitted from heavy duty vehicles. Particulate matter (PM) emission factors generated by MOVES are vehicle speed dependent while MOBILE6.2 shows no such dependence. In the second part of the study, the impact of replacing MOBILE6.2 with MOVES in predicting regional air quality in Southeast Texas is studied in detail using the EPA’s Community Multiscale Air quality Model CMAQ (version 4.7.1) for an air quality episode from August 28th to September 15th 2006. Simulation with MOVES emissions showed higher concentrations of NOx and lower concentrations of EC compared to a simulation with MOBILE6.2 generated emissions. Ozone concentrations are decreased by as much as 5 ppb at urban areas and decreased in rural areas by as much as 3 ppb due to differences in the NOx dependence in the photochemistry. The model performance for 8-hour average ozone concentration is slightly better using the MOVES emissions.

• Supplemental Notes:
  • This paper was sponsored by TRB committee ADC20 Transportation and Air Quality
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Kota, Sri Harsha
  • Ying, Qi
  • Schade, Gunnar W
• Conference:
  • Transportation Research Board 91st Annual Meeting
  • Location: Washington DC, United States
  • Date: 2012-1-22 to 2012-1-26
• Date: 2012

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; References; Tables;
• Pagination: 15p
• Monograph Title: TRB 91st Annual Meeting Compendium of Papers DVD

Subject/Index Terms

• TRT Terms: Air quality management; Alternatives analysis; Exhaust gases; Mathematical prediction; Particulates; Pollutants; Simulation; Urban areas
• Identifier Terms: MOBILE (Computer model); Motor Vehicle Emission Simulator (MOVES)
• Geographic Terms: Texas
• Subject Areas: Energy; Environment; Highways; I15: Environment;

Filing Info

• Accession Number: 01367695
• Record Type: Publication
• Report/Paper Numbers: 12-4438
• Files: TRIS, TRB
• Created Date: Apr 11 2012 11:11AM