5. On behalf of the Informal Working Group (IWG) on UN Regulations Nos. 51 and 59, the expert from OICA introduced a revised proposal for the 03 series of amendments to UN Regulation No. 51 (ECE/TRANS/WP.29/GRB/2014/5). He explained that the text of this proposal was harmonized, as far as possible, with European Union (EU) Regulation No. 540/2014 on the sound level of motor vehicles and of replacement silencing systems, including a three-phase reduction of the sound level limits. GRB noted that, following the entry into force of phase 2 for new types of vehicles, EU would undertake a detailed study to review the limits of phase 3 and to correct these values, if deemed to be necessary. Other Contracting Parties were invited to conduct similar studies in the future and to transmit their outcomes to GRB. GRB stressed the importance of aligning the timeline for introduction of phases 1-3 of the 03 series of amendments to UN Regulation No. 51 with the step-by-step entry into force of the above EU Regulation. For this reason, GRB agreed that all transitional provisions of paragraph 11. of the proposal should refer to specific dates(i.e., dates identical to those of the EU phase-in). Finally, GRB adopted the proposal, as amended by Annex III to this report, and mandated the secretariat to submit it to WP.29 and AC.1 for consideration and vote at their March 2015 sessions.

6. The expert from Japan suggested that references to ISO 10844:2011 be put in square brackets for the time being and requested GRB to revert to this issue at the next session.

8. GRB noted that the additional sound emission provisions contained in ECE/TRANS/WP.29/2011/64 had been incorporated into the revised proposal for the 03 series of amendments to UN Regulation No. 51 (ECE/TRANS/WP.29/GRB/2014/5) and decided to remove ECE/TRANS/WP.29/2011/64 from the agenda.

9. GRB recalled that, at its previous session, it had adopted the draft 03 series of amendments to Regulation No. 51 (ECE/TRANS/WP.29/GRB/2014/5, ECE/TRANS/WP.29/GRB/58, para. 5 and Annex III) which had subsequently been submitted to WP.29 and AC.1 for consideration and vote at their March 2015 sessions as document ECE/TRANS/WP.29/2015/3. With regard to the additional proposals adopted at this session (para. 8 above and Annex III to this report), GRB noted two options for their processing:

• (i) submit them separately to WP.29 and AC.1 for consideration and vote at their June 2015 session as a draft Supplement 1 to the 03 series of amendments to Regulation No. 51; or
• (ii) combine them with the 03 series of amendments to Regulation No. 51 (ECE/TRANS/WP.29/2015/3) in a single document and submit it to WP.29 and AC.1 for consideration and vote at their June 2015 sessions. In this case, WP.29 and AC.1 would be requested not to consider document ECE/TRANS/WP.29/2015/3 in March 2015.

10. GRB supported option (ii) and mandated its Chair to report about this decision to WP.29, AC.1 and the Administrative Committee for the Coordination of Work (AC.2) at their sessions in March 2015. GRB also noted that IWG on UN Regulations Nos. 51 and 59 had completed its tasks and that the extension of its mandate was not necessary.