8. On behalf of a group of experts, the expert from OICA proposed a number of amendments updating and revising the 03 series of amendments to Regulation No. 51 (ECE/TRANS/WP.29/GRB/2017/6). These proposals received comments from the experts of China, Russian Federation and Switzerland (GRB-66-11, GRB-66-13 and GRB-66-19). The expert from OICA also proposed some further modifications (GRB-66-20).

9. The expert from Italy expressed concerns about the suggested extension of the sound pressure level measurement to line BB’ plus 20 m, with the aim to properly assess the possible “backfire”. According to him, this modification would be a new requirement which should be introduced by means of a new series of amendments with transitional provisions, rather than by a supplement, as proposed in ECE/TRANS/WP.29/GRB/2017/6. He also pointed out that the above modification would need to be accompanied with a similar change in the relevant ISO standard. The experts from Germany, Japan, Sweden and Switzerland supported this amendment proposal in the form of a supplement. The expert of the Russian Federation supported the proposal as a supplement and agreed that Regulation No. 51 and the ISO standard should be aligned. The experts from France and EC were of the view that a new series of amendments would be more appropriate.

13. On behalf of IWG ASEP, the expert from France presented its status report to GRB (GRB-66-14). In particular, IWG ASEP had agreed to propose some improvements in the current Annex 7 as soon as possible, as laid down in ECE/TRANS/WP.29/GRB/2017/5, and then to develop a more general and strategic approach of revising Annex 7. The expert from the Russian Federation commented on ECE/TRANS/WP.29/GRB/2017/5 (GRB-66-06). GRB agreed to merge these proposals with the other proposed amendments to the 03 series of amendments to Regulation No. 51 (see para. 9 above).