Overview of discussions for the future development of vehicle noise regulations prepared by the GRB secretariat.

This proposal further refines and clarifies the 03 series of amendments to UN R51 from Informal Working Group on UN Regulations Nos. 51 and 59. The 03 series was proposed in document GRB/2014/5 which was amended and then adopted by the Working Party on Noise during its 60th session. The proposal includes special provisional limits for Chinese micro-vehicles which are being reviewed by Japan.

Proposal to clarify the wording of the 03 series of amendments to UN R51 as adopted by the World Forum in June 2015 (document WP.29/2015/62). The adopted wording could lead to the interpretation that sound levels measured on the left side of the vehicle are to be averaged with levels measured on the right side of the vehicle. The proposed new wording clarifies that the overall sound emission is assessed individually per vehicle side.