Air pollution caused by motor vehicles is one of the most serious problems of civilized society. The aim of this paper is to develop a decision support system that can be used by authorities to reduce air pollution from road transport. The essence of this system consists of mathematical sub-models based on the computer program methodology for calculating emissions from road transport, (COPERT IV) and (CALINE3) – a versatile dispersion model for predicting air pollution levels near highways and arterial streets, in order to simulate the models of air pollutant emission and dispersion in the area along the Belgrade-Niš highway. These sub-models were integrated into a geographic information system (GIS), which was used for selecting critical areas where air pollution levels were above limits.
The results showed the simulation of pollutant dispersion in two scenarios. In the first scenario, in the worst weather conditions, the concentrations of particulate matter (PM) and sulphur oxides (SO₂) are the highest in more grids than in the case of two other pollutants, but the concentrations of carbon monoxide (CO) and nitrogen oxides (NO_x) are more widespread. Moreover, the overall pollutant concentration is the highest in the area of Požarevac-V.Plana. In the second scenario, the concentration of all four parameters is the highest in the summer due to NW wind direction, and in autumn due to SE wind direction. It can be concluded that meteorological parameters and transportation characteristics have a significant influence on emission and dispersion of air pollutants.