Vehicular activities are the major sources of NOx emissions including other pollutants. Due to hasty growth of vehicles augmented emission levels of pollutants causing severe damage to human health and environment. This paper represents the assessment of NOx produced by vehicles at traffic rotatory at GoleKaMandir in Gwalior city by using mathematical modeling approach. Mathematical model like General finite line source model (GFLSM) and Delhi finite line source model (DFLSM) are used to assess NOx level in this study. An emission inventory was prepared for vehicles around the rotatory in three shifts viz. Early morning (EM) (04:00 to 06:00), Morning (MO) (07:00 to 11:00) and Evening (EVE) (07:00 to 11:00). Meteorological data are observed during sampling time at a regular interval of one hour. Predicted data which are simulated by the model and subsequently compared by the observed data of same period were obtained by monitoring through (APM 410) High volume sample. GFLSM holds well with the observed data in comparison to DFLSM as the average value of NOx (in μg/m3) 33.81 and worked out as, 36.40 and 0.1 through GFLSM and DFLSM. Statistical analysis for the performance of the models reveal GFLSM hold good in comparison to other model with respect to Correlation coefficient (r), Root mean square error (RMSE), and Degree of agreement (d). It is concluded that the levels of NOx at study area are below NAAQS 2009 norms and GFLSM shows a good response for the prediction of NOx level in this study area.

Keywords : Vehicular emission, NOx, Emission inventory, Meteorology, Mathematical model, GFLSM, DFLSM, Statistical analysis, Performance Evaluation.