25. GRB noted that WP.29, at its March 2009 session, had endorsed the proposal to set up an informal group on Minimum Sound Levels for silent vehicles (MSL). The expert from Japan introduced GRB-50-08 regarding a study on approach audible systems for hybrid and electric vehicles. He also presented a number of sample sounds (steady and non-steady) for approaching silent vehicles. The expert from the United States of America stressed the need that such sounds should not only be similar to that emitted by combustion engine, but also indicate the speed, direction as well as the acceleration or deceleration of the vehicle. He recalled that this information was important, especially for visually-impaired people.

26. The expert from the United States of America reported on the work progress made in his country on silent vehicles with regard to the safety of blind pedestrians (GRB-50-09). GRB agreed with his suggestion to hold a first meeting of the informal group on MSL prior to the next GRB session, in Geneva on Monday morning 15 February 2010. For that purpose, GRB reminded the expert from the United States of America to prepare the draft Terms of Reference of the informal group for consideration at the next GRB session.