Evaluation of CO and NOx Emissions from MOVES and MOBILE6.2 in Southeast Texas Using Source-Oriented CMAQ Model

The MOBILE series emission factor models are replaced by Motor Vehicle Emission Simulator (MOVES) in 2012 as an official tool recommended by US Environmental Protection Agency (EPA) to predict vehicular pollutant emission factors. In this study, on-road vehicle emission inventories of CO and NOx for Southeast Texas generated by MOVES and MOBILE in two versions of the 2005 National Emission Inventory (NEI) are studied by comparing predicted CO, NOx and CO/NOx ratios with measurements using the EPA’s Community Multiscale Air Quality (CMAQ) Model incorporated with a source-oriented gas phase chemical mechanism. This source tracing technique allows direct determination of contributions from gasoline and diesel vehicles to CO and NOx concentrations and identification of stations which are impacted by vehicle emissions. At three vehicle-emission influenced stations, MOVES estimates higher NOx and relatively similar CO compared to MOBILE6.2 (version 6.2 of the MOBILE model). Results indicate that MOVES overestimates NOx by 50% compared to 6% based on MOBILE emissions. Even though MOVES does a slightly better job in predicting CO/NOx ratios than MOBILE6.2, this difference is primarily due to inaccurately increasing NOx rather than decreasing CO emissions. This study suggests that the current version of the MOVES model should be improved to reduce NOx to the levels slightly below MOBILE predictions and significantly reduce CO 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
  • Zhang, Hongliang
  • Schade, Gunnar W
• Conference:
  • Transportation Research Board 92nd Annual Meeting
  • Location: Washington DC, United States
  • Date: 2013-1-13 to 2013-1-17
• Date: 2013

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; References; Tables;
• Pagination: 13p
• Monograph Title: TRB 92nd Annual Meeting Compendium of Papers

Subject/Index Terms

• TRT Terms: Carbon monoxide; Computer models; Exhaust gases; Mathematical prediction; Nitrogen oxides
• Identifier Terms: Community Multiscale Air Quality (CMAQ) model; MOBILE6.2 (Computer model); Motor Vehicle Emission Simulator (MOVES)
• Geographic Terms: Texas
• Subject Areas: Environment; Highways; I15: Environment;

Filing Info

• Accession Number: 01475668
• Record Type: Publication
• Report/Paper Numbers: 13-5187
• Files: TRIS, TRB, ATRI
• Created Date: Mar 15 2013 9:47AM