94. The representative of the United Kingdom reported on the work progress of the IWG on Phase 2 of UN GTR No. 7 (WP.29-163-23). He recalled the main challenges of the IWG: (i) the effective and absolute height measurement of the head restraint and (ii) the introduction of the BioRID dummy in the UN GTR as a test tool. He clarified that the effective height measurement method of the head restraints had been finalized, based on a repeatable geometric process that excluded styling features with no restraining purposes. The IWG concluded that, concerning the establishment of a maximum absolute height value of the head restraints, the ultimate decision could only be taken by Contracting Parties during GRSP proper sessions. He informed AC.3 that the National Highway Traffic Safety Administration (NHTSA) had extensively conducted cadaver testing to allow the IWG to correlate cadaver response with performance of BioRID and establish injury criteria. However, he said that reproducibility of dummy performances were critical, because of the need to replace banned chemical materials used in dummy components. He added that this issue could delay the delivery of a complete proposal. However, he stated that the IWG was expected to submit an informal draft proposal at the December 2014 session of GRSP and complete discussion on the basis of an official document at the May 2015 session of GRSP. He suggested that AC.3 consider the possibility to separate the BioRID issue and head restraint height measurement from the proposal of amendment to the UN GTR. The representative of OICA recalled that AC.3 had already decided to request GRSP to recommend a proposal including both issues. AC.3 agreed to defer decision on this issue to its November 2014 session. The secretariat was requested to distribute WP.29-163-23 with an official symbol at the November 2014 session of AC.3.