11. The expert from the Russian Federation introduced some clarifications to be included in UN Regulation No. 117, on data processing for the measurement method of tyre deceleration value obtained in differential form dω/dt (ECE/TRANS/WP.29/GRB/2014/7). GRB adopted this proposal, as amended by Annex V to this report, and requested the secretariat to submit it to WP.29 and AC.1 for consideration and vote at their March 2015 sessions.

17. The experts from France, the Russian Federation and ERTRO informed GRB (GRB-59-07 and GRB-59-08) about the outcome of their ad hoc meeting on testing the “Deceleration Calculator” software proposed by the Russian Federation for the deceleration test method using the dω/dt form for measuring rolling resistance. GRB noted that the ad hoc meeting had been hosted by the Technical Union for the Automobile, Motorcycle and Cycle Industries (UTAC), and generally included both theoretical justification of the method and its experimental assessment by determining rolling resistance of a sample tyre of class C1 using two test machines of different types. GRB also noted that the obtained data, its processing and statistical assessment had demonstrated good adaptability of the software to the tyre test machines and satisfactory reproducibility of deceleration data. Moreover, the algorithm of the “Deceleration Calculator” practically provides independence of the measured deceleration from the test speed range in span from 4 to 20 km/h.

18. Therefore the expert from the Russian Federation proposed GRB-59-02 superseding ECE/TRANS/WP.29/GRB/2013/10, as an alternative for measurements and data processing for deceleration value obtaining in differential form dω/dt.

19. GRB agreed in principle with the proposed method. However, given the late availability of GRB-59-02, GRB suggested that this document, accompanied by other supporting materials (GRB-59-07 and GRB-59-08), be first submitted to the forthcoming February 2014 session of GRRF for discussion and then, together with GRRF comments, transmitted as an official document to the next GRB session in September 2014 for final consideration. In the meantime, it was noted that results of testing tyres of commercial vehicles (classes C2 and C3) could also become available for that session of GRB. Finally, GRB invited experts to provide comments, if any, to the secretariat before the next GRB session.

20. The expert from ERTRO introduced GRB-59-03 containing a revised proposal for new time measurement accuracy for instrumentation involved in the rolling resistance method, with the aim to correct inconsistencies in Annex 6 to the UN Regulation. The proposal text was also supported by the experts from the Russian Federation. The expert from Japan raised a study reservation to verify the consequences of the change of accuracy. The expert of the European Commission raised similar concerns and stated that he would need first to discuss this matter with ERTRO on a bilateral basis. GRB agreed to resume consideration on this subject at its September 2014 session and requested the secretariat to distribute GRB-59-03 with an official symbol