Prediction of PM2.5 along urban highway corridor under mixed traffic conditions using CALINE4 model

•PM2.5 emission estimated along a highway under mixed traffic using CALINE4 model.•Traffic, micro-meteorological parameters and PM2.5 concentration measured on-site.•Settling and deposition velocity of PM2.5 were estimated.•Statistical evaluation indicated unsatisfactory performance of model for PM2.5.•Study indicated various limitations of CALINE4 model for PM2.5 predictions.

The present study deals with spatial-temporal distribution of PM2.5 along a highly trafficked national highway corridor (NH-2) in Delhi, India. Population residing in areas near roads and highways of high vehicular activities are exposed to high levels of PM2.5 resulting in various health issues. The spatial extent of PM2.5 has been assessed with the help of CALINE4 model. Various input parameters of the model were estimated and used to predict PM2.5 concentration along the selected highway corridor. The results indicated that there are many factors involved which affects the prediction of PM2.5 concentration by CALINE4 model. In fact, these factors either not considered by model or have little influence on model's prediction capabilities. Therefore, in the present study CALINE4 model performance was observed to be unsatisfactory for prediction of PM2.5 concentration.