6. On behalf of the Informal Working Group on Additional Sound Emission Provisions (IWG ASEP), the expert from Germany reported on the IWG ASEP activities (GRBP-71-25). He also introduced in detail the future revision of ASEP in UN Regulation No. 51, based on the concept of real driving and sound expectation model (GRBP-71-24).

7. The expert from IMMA pointed out the differences in applying the concept of real driving between UN Regulation Nos. 41 and 51 (GRBP-71-19-Rev.1) and introduced draft revised ASEP provisions in UN Regulation No. 41 (GRBP-71-17). The Chair invited IMMA to continue working on this proposal in the framework of IWG ASEP with the aim to submit a formal document to the next session of GRBP.

8. The expert of EC informed GRBP about a study on the sound level limits of M- and N-category vehicles which had started in December 2019 and was expected to be completed by June 2021 (GRBP-71-11). The aim of the study was to propose improved sound level limits for next phases of Regulation No. 540/2014 of the European Union in the coming years. The experts from Germany, ETRTO and OICA encouraged the study contractor to follow a holistic approach and to take into account various factors that contribute to sound emissions. GRBP invited those experts to send their comments to the contractor and requested the expert of EC to regularly inform GRBP about the study progress. The expert from Japan pointed out that his country would launch soon a similar study and that the recommendations of both studies should be harmonized internationally.

9. The expert from OICA reported on the progress of the Task Force on Measurement Uncertainties (TF MU) (GRBP-71-04) and presented a strategy on how to handle measurement uncertainties in UN Regulations (GRBP-71-21). GRBP noted that the suggested approach could first apply to UN Regulations Nos. 51 and 117 and, at a later stage, to other UN Regulations as well.

10. Given the importance of this topic, GRBP decided to convert TF MU into an Informal Working Group on Measurement Uncertainties (IWG MU) and approved its Terms of Reference (GRBP-71-05, GRBP-71-31-Rev.1), as laid down in Annex IV. GRBP noted that IWG MU would be chaired by Norway, while OICA would act as secretary.