CWA 17379:2019: A new CEN Workshop Agreement helps make our air cleaner 

CEN Workshop Agreement CWA 17379:2019 ‘General guideline on real drive test methodology for compiling comparable emission data’ is the latest example of the active role of standardization in improving air quality for all Europeans, especially in urban areas. For the first time ever, the publication provides a testing methodology and guidelines recognised all over Europe to conduct on-road testing of cars and vans to capture data on emissions of urban nitrogen oxides (NOx). In particular, the methods and requirements described in the agreement ensure that the test procedure, conducted using Portable Emissions Measurement Systems (PEMS), is consistently applied. The data thus collected will enable emissions performance of different vehicles, across different test centres, to be fairly compared.

Since the 1st of September 2017, the type approval of all newly introduced cars includes on-road testing as part of the latest emissions standard known as RDE (Real Driving Emissions). This European certification process was developed and implemented to ensure modern vehicles do not exceed the prescribed emissions limits in normal use across a range of driving conditions.

CWA 17379:2019 builds upon the RDE methods and describes the process to test the actual emissions recorded during urban driving, with the aim of comparing the on-road emissions performance of different vehicles fairly. The stringent requirements introduced demand the testing of at least two matching examples of each model, during three separate journeys, including at least five 10km trips conducted on paved roads, at an average speed between 20km/h and 40 km/h.

The results produced using this methodology provide transparency regarding the on-road NOx emissions produced from vehicles during urban driving. This enables car buyers, policy makers and other stakeholders to take better informed decisions about vehicle choices and the consequences for urban air quality.

CEN CWA 17379:2019 was published on 30 January 2019 by CEN/WS 090 “Real drive test method for collecting emission”. The agreement is the result of a collective dialogue between more than 40 scientists, consumer groups, policy makers, engineers, NGOs and the European Commission, working together under the chairmanship of Nick Molden, founder of Emissions Analytics and co-founder of Allow Independent Road-testing (AIR). The Secretariat of CEN/WS 090 was held by UNI, the Italian National Standardization Body.
















For more information, please contact Thierry Legrand