ASSESSMENT OF THE ECONOMY OF MUNICIPAL BUS OPERATION

The aim of the research was focused to evaluate operational economy of two identical buses with using two different fuels. Research concerning economy of bus operation was ordered on request by the transport company that operates the buses. The transport company that operates the buses requested the survey to verify the operational economy of bus vehicles with the engine on combustion of CNG. Only the costs associated with fuel consumption were counted. The cost at acquisition of the vehicle and the cost of service inspections were not counted into this project. The measurements were conducted in the city of Nitra and the bus route constituted the route where the buses are operated. The buses were alternated at regular intervals on the same bus route. Driver A drove on the bus SOR BN 12 Ekobus City Plus (Bus 1) with the engine CUMMINS WESTPORT Plus. This type of combustion engine was rebuilt on combustion of compressed natural gas (CNG). Driver B drove on the bus SOR BN 12 (Bus 2) with classic diesel engine. Technical parameters of both engines are identical. The only difference is in the type of fuel. The base for data processing consisted of the work evidence of the drivers in the form of recording sheets determining the actual fuel consumption. The paper comprises assessment of fuel consumption by both drivers as recorded in the bus log books and finally at comparing the fuel consumption in particular months. Since the survey was conducted during the period November 2014 to October 2015, 12 record sheets were completed.