CESTiCC: Impact of Cold Climates on Vehicle Emissions: Cold Start Air Toxics Pulse

AIDC project number: 101409


Tom Jobson



  • Start Date: May 1, 2014
  • End Date: Apr 30, 2016

Project Documents

Project Final Report

Project Summary

Vehicle emissions models, such as the US EPA’s Motor Vehicle Emissions Simulator (MOVES) suggest that in cold climates, the majority of pollutant mass emitted by vehicles occurs during engine cold starts and idling and not when the vehicle is moving along the road.  In winter, cold starts in combination with meteorological conditions that trap vehicle emissions under low lying temperature inversions lead to significantly elevated pollutant concentrations.  People living in colder climates are potentially exposed to significantly higher concentrations of air toxics than in warmer climates because of enhanced cold start and idling emissions and lower pollution dispersion rates.   However, vehicle emissions data for cold climates is sparse and the accuracy of vehicle emissions model parameterizations for air toxics in cold climates is not known.  Clarifying the importance of vehicle cold start and engine idling emissions in cold climates is the focus of this study. We will measure cold start emissions from gasoline and diesel engine vehicles during the winter months in our engine testing building.