Air quality impact assessment of NOx and PM due to diesel vehicles in Delhi

The impact of diesel vehicles on NOx and PM emissions at various locations in Delhi is assessed using two line source models; the California line source version 4 and the Indian Institute of Technology Line Source. The models offer comparable results but both under predicting the observed values with the Indian Institute of Technology model predictions being slightly better. The analysis also identifies hotspots due to concentrations of NOx and PM and their diurnal variations is found to be greater in at night hours.