A methodology was developed to project total vehicular emissions from different emission reduction policies for the light-duty vehicles in the roads network of Tehran, Iran. A road-link-based model was constructed based on a bottom-up approach by coupling COPERT emission functions with the travel demand model of EMME/2. Results showed total emission from the studied network was largely impacted by vehicles’ technology and age, speeds in the links, and fuel type. The proper transportation management to reduce the part of passenger cars and improve traffic flow also leads to a significant drop in the emission, e.g., emission decreased by 43% from 20% traffic volume reduction. Results indicated the importance of concurrent implementation of practices for effective emission reduction. Enforcing proper emission standards, expanding public transportation, and vehicles’ fleet renewal can potentially reduce more than 90% of current CO emission.
Keywords: air pollution, on-road emission, light-duty vehicles, emission modelling, Tehran, CO, NO x, hydrocarbons, environmental policy