30. The expert from ETRTO recalled ECE/TRANS/WP.29/GRRF/2011/13 and ECE/TRANS/WP.29/GRRF/2011/14, harmonizing the definitions used in Regulations Nos. 30 and 54 with those of the 02 series of amendments to Regulation No. 117. The expert from Germany underlined that some proposed definitions diverged with those used within the European Union. The expert from France proposed in GRRF-71-31 to further develop the definition of snow tyre and to align the snow tyre markings requirements in Regulations Nos. 30, 54 and 117. GRRF agreed to continue consideration of that matter at its February 2012 session on the basis of a proposal prepared by France in collaboration with experts from Germany, the European Commission, OICA, ETRTO and all the interested experts (Focal point: Mr. Lescail from France: lescail@utac.com).

31. GRRF agreed to consider GRRF-71-28 at its next session and requested the secretariat to make it available with an official symbol.

12. The expert from the Russian Federation introduced ECE/TRANS/WP.29/GRB/2011/11, aimed at improving the test provisions for measuring the rolling resistance of tyres. The proposal received several comments (GRB-54-02, GRB-54-08 and GRB-54-10 amongst others). The Chair of GRB introduced GRB-54-12-Rev.1 proposing to amend ECE/TRANS/WP.29/GRB/2011/11. He clarified that the proposal did not affect the existing methods but result in a further option to the deceleration method. GRB adopted ECE/TRANS/WP.29/GRB/2011/11 as reproduced by Annex III to this report. However, some GRB experts suggested further technical assessment of the proposed alternative method to the next GRB sessions. The secretariat was requested to submit the proposal to WP.29 and AC.1, for consideration at their March 2012 sessions, as draft Supplement 1 to the 02 series of amendments to Regulation No. 117.

13. GRB noted also the work progress of the Working Party on Brakes and Running Gear (GRRF) on matters of common interest with GRB (ECE/TRANS/WP.29/GRRF/2011/12, ECE/TRANS/WP.29/GRRF/2011/29, ECE/TRANS/WP.29/GRRF/2011/30, GRRF-69-23, GRRF-71-29 and GRRF-71-31). Particularly, GRB endorsed ECE/TRANS/WP.29/GRRF/2011/30, inserting a new definition of C3 class tyres adopted by GRRF at its September session.