In Europe, the exhaust emissions of automobiles and light commercial vehicles can be evaluated under defined environmental conditions in the laboratory with the help of the New European Driving Cycle (NEDC). With this evaluation, only part of the driving conditions in real traffic can be assessed. However, practice has shown that in actual driving on roads the emissions’ nitrogen values, especially from diesel vehicles are significantly higher than those in the lab.
Real-Driving-Emissions (RDE) is a process that measures and assesses the automobile emissions under actual driving conditions. One way of measuring actual driving emissions is by applying mobile measuring instruments. A Portable Emission Measurement System (PEMS) is installed in the vehicle and thus facilitates the measurement of exhaust emissions.