One of the ways to reduce exhaust emissions from vehicles is to replace worn-out shunting locomotives with road-rail tractors. The main purpose of this solution is to reduce the negative environmental impact of the vehicle and to reduce the fuel consumption compared to a shunting locomotive performing the same work. The tests on exhaust emissions of rail vehicles are carried out on an engine test bench, making it impossible to determine the environmental performance of these vehicles during real operation. Therefore, it is advisable to carry out measurements in real operating conditions in order to obtain reliable reference results. This enables the verification of vehicles ecological indicators in a wide range of operational work parameters. It is possible to obtain reliable results regarding the impact of the tested vehicle on the natural environment in this way and compare them with the applicable emission standards.