CALINE 4 highway dispersion model is extensively used all over the world including India for prediction of vehicular pollution along highway corridors. A few studies have reported its application and suitability under complex/hilly terrain. In the present paper, an attempt has been made to evaluate the performance of CALINE 4 model in hilly terrain for Indian traffic and meteorological conditions. CALINE 4 model predictions have been compared between flat and hilly terrains along two road corridors in Solan District in the state of Himachal Pradesh (India). The statistical indicators of the model performance such as, index of agreement (d), fractional bias (FB), and normalised mean square error (NMSE) reveal that the model performed satisfactorily in the flat terrain. However, model fell short in explaining the complexity of terrain and performed unsatisfactorily in hilly terrain conditions.
Keywords: CALINE 4 model, hilly terrain, vehicular emission, emission load, performance evaluation