Research into the costs of vehicle exhaust gases from the standpoint of using natural gas-powered buses

This paper aims at analysing the costs of motor vehicle exhaust gases with particular reference to natural gas-powered buses in intercity passenger transport in the territory of the Republic of Serbia. For defining and forecasting transport demands, expressed in the number of vehicles per day at each section of the created multimodal transport network, Transtools application is used, specially adapted for the territory of the Republic of Serbia. By applying the Highway Design and Maintenance (HDM) model and regression analysis, the functional dependency between the speed of a vehicle and fuel consumption is established for each of the following categories: passenger car, bus, light truck, medium truck, heavy truck, articulated truck, according to the type of the terrain and International Roughness Indicator (IRI) of the road. By estimating the unit costs of NOx, NMVOC, SOx, PM, CO, CO2 and CH4 pollutants and by estimating the average factors of exhaust emissions expressed in a gram of pollutant/gram of burnt fuel, according to all vehicle categories, the analysis of exhaust gas emission costs is conducted for three different scenarios.