Natural Gas Buses in Serbia Public Transport - Some Operational Experiences

The state of development and application of compressed natural gas (CNG) buses in Serbia is presented, together with a review of their number in some European countries and cities. After several years of operation of these buses in the largest fleets in Serbia (Belgrade and Novi Sad), an analysis of their economic benefits and ecological characteristics has been carried out. Special attention is paid to the operational costs and possible savings achievable by CNG buses compared to diesel buses. Ecological characteristics of these buses are presented through the measurements of exhaust emissions on one type of these buses and through presentation and analysis of data from the literature on emissions of the buses of identical or similar engines. The preformed investigations show that application of CNG buses brings significant savings as regards total costs during their operational lifecycle compared to diesel buses. On the other hand, CNG buses have a significant ecological potential as regards fulfilling stringent requirements for exhaust emissions standards