4. The expert from IWG ASEP GRBP introduced a proposal that aimed to clarify the current wording of UN Regulation No. 51 (ECE/TRANS/WP.29/GRBP/2022/3). GRBP adopted the proposal, as amended by GRBP-75-36 and subject to deletion “or later” for the ISO standard references in Annexes 3 and 8, and requested the secretariat to submit it for consideration and vote at the June 2022 sessions of WP.29 and AC.1 as a new Supplement to the 03 series of amendments to UN Regulation No. 51.

6. The expert from Norway, in his capacity of Chair of IWG MU, presented proposals that introduced a temperature- and test-track compensation for vehicle noise (ECE/TRANS/WP.29/GRBP/2022/8). GRBP adopted the proposal, subject to the a correction of the equation for the mean value of logarithms of speeds vi in Annex 3, Appendix 3, paragraph 4.3. See the session report for the corrected formula.

7. GRBP requested the secretariat to submit the proposal for consideration and vote at the June 2022 sessions of WP.29 and AC.1 as a new Supplement to the 03 series of amendments to UN Regulation No. 51.

8. The expert of IWG MU proposed to align the entry into force of draft Supplements (GRBP-75-04-Rev.1). GRBP agreed to request WP.29 and AC.1 to postpone to their June 2022 sessions consideration of draft Supplement 7 to the 03 series of amendments to UN Regulation No. 51 (ECE/TRANS/WP.29/2022/4), in order to combine it into a consolidated proposal with the amendments mentioned in paragraphs 4, 5 and 7 above.

9. The expert from China proposed to extend the transitional period in paragraph 11.8. of the 03 series of amendments to UN Regulation No. 51, due to the difficulties in meeting the noise limits by microvans and micro-trucks available at the national market (GRBP-75-40 and GRBP-75-41). GRBP agreed to extend the transitional period until the end of 2023 and requested the secretariat to include this modification in draft Supplement 7 to the 03 series of amendments to UN Regulation No. 51 (paragraph 8 above). For any further extension, GRBP invited the expert from China to submit an official document to the next session.