Transportation conformity is a way to ensure that Federal funding goes to those transportation activities that are consistent with air quality goals. In the past, the DCHC MPO was a nonattainment area and maintenance area for air quality, and therefore was required to demonstrate air quality conformity. This demonstration was basically done by showing that several future hazardous emissions from the transportation sector would be below a set threshold.
The Motor Vehicle Emission Simulator (MOVES) model is used to forecast future emissions. The model develops emissions factors using information such as vehicle age and type distribution, and combines that data with output from the travel demand model, Triangle Regional Model (TRM), such as vehicle miles traveled (VMT) and average speeds. It ultimately forecasts the level of various hazardous emissions such as carbon monoxide, particulate matter and nitrous oxides that are emitted from the transportation sector.
For information on the MPO use of MOVES, see this MPO Air Quality Web page