Text prepared by the GRB Expert Group on Regulation 51 and revised during the GRB-59 session consolidating the proposed 03 series of amendments to UN Regulation No 51 developed during the informal group’s fourth meeting in Brussels on July 4 plus additions from November 8. This version removes references to “acoustic vehicle alerting systems” (AVAS)

Proposal (revised from its earlier version) to allow horn sound level testing with the engine running and lower the sound pressure level requirement for light-duty vehicles from 93 dB (A) to 90 dB (A).

Testing and Evaluation of the variant method using the dω/dt form.