Fuel Consumption Analysis of CNG and Hybrid Buses on the Road Network

In this paper fuel consumption and fuel costs of CNG and hybrid buses are analyzed in intercity bus service in the Republic of Serbia. In order to define and forecast transport demands in average annual daily traffic, on every section of the multimodal transport network, the application Transtools was used. This application of Transtools was specially adapted to suit the territory of the Republic of Serbia. By applying the Highway Development and Management (HDM) model and regression analysis, in accordance with the type of terrain and the International Roughness Indicator (IRI), the functional dependency between the speed of a diesel bus and its fuel consumption was determined as a polynomial of the second level. By determining fuel equivalents of CNG and hybrid buses and based on the research which was carried out in real operating conditions, a projection of fuel consumption for alternative concepts was made on the entire road network for three different scenarios which describe different road and operating conditions. Fuel cost analysis is carried out on the entire modeled road network. Also, the economic analysis of using CNG and hybrid buses on a real intercity line was made considering investment, operating and maintenance costs of buses from the standpoint of bus fleet owners.