Driving, flying and trips by bus or rail are a part of our daily lives. Problems in these areas are often noticed by, and can have an impact on, a large segment of the population. Emissions from transportation are responsible for most nitric acids in rain, increasing ground level ozone, a substantial fraction of fine particulate matter and some persistent organic pollutants.

The modelling of emissions from transportation sources requires specially designed emission estimation models and dispersion models. The emission estimation models take into account the age of the fleet, the mix of diesel and gasoline powered vehicles and vehicle inspection programs. The transportation air dispersion models take into account the turbulence created by the vehicles as they drive along the roadways. Some models can model traffic signal lights and their impact on traffic flows, contaminant emissions and the resulting concentrations.

MOBILE - For the emission estimates in Canada, the current model is MOBILE5C and in the USA, MOBILE6 is used.
PART5 - This model is designed for emission estimates of PM10 and SO2 from tail pipes of automobiles as well as road dust.
EDMS - EDMS is a combined emission/dispersion model for assessing pollutants from civilian and military airports.
CALINE3/4 - CALINE can be used to calculate concentrations of non-reactive pollutants from highway traffic.
CAL3QHC - The CAL3QHC model can be used for predictions of CO or other inert pollutant concentrations from motor vehicles on road networks and at roadway intersections.