Assessment of the Environmental Costs of Rail Buses in Poland Based on Research in Real Operating Conditions

The article analyzes the environmental costs of Diesel Multiple Unit and Diesel Railcars operated in Poland.It consisted in determining the annual cost of gases and particulate matter emitted into the ambient air by the analyzed rolling stock.For this purpose, tests were carried out on the emission of harmful exhaust gases from a railbus equipped with the most commonly used drive system.The vehicle had two identical compression ignition engines meeting the Stage IIIB standard with a displacement of 12.8 dm 3 .Maximum power of the engine was 390 kW at a rotational speed of 1800 rpm and a maximum torque of 2200 Nm at 1300 rpm.In order to measure harmful exhaust compounds, tests were carried out in real operating conditions using Portable Emission Measurement System (PEMS) equipment.The tests carried out in track conditions showed that the rail vehicle did not meet the approval limits for nitrogen oxides (real value -2.43 g/kWh, emission standard -2.0 g/kWh).However, it should be remembered that the limit values are established in stationary tests and not in actual operating conditions.In the next stage, the annual emissions of rail buses operating in Poland were estimated.For this purpose, data from the Office of Rail Transport on the number of vehicles registered in the country and the average distance traveled by the vehicles were used.The data obtained indicate that the vast majority (over 98%) of environmental costs are costs related to carbon dioxide emitted into the atmosphere.