CALINE4 line source dispersion tool has been applied to model NOx in the study with the help of CALROADS View software. The model was used with and without canyon options activated near Jadavpur University, Kolkata. It is observed to exhibits better correlation for ‘with canyon’ option than ‘without canyon’ against actually measured concentrations of NOx, which is indeed more realistic to reflect actually prevailing condition, as the study site is situated in a street canyon. A calibration equation is also deduced to calculate the corresponding actual i.e. prevailing concentrations form model predicted values for NOx. A typical NOx concentration contour due to traffic is generated around Jadavpur University, Kolkata. Read more..