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).
34. The expert from OICA introduced GRB-59-06-Rev.1 to update the test conditions and provisions of UN Regulation No. 28: (i) to allow the test of the audible warning devices on the vehicle with its engine warmed-up and at idle and (ii) to reduce the prescribed sound level from 93 to 90 dB(A). He justified the second point because this reduced level was audible far enough to instantaneously warn pedestrians and other road users, including drivers, as it was typically 20 dB to 40 dB higher compared to typical traffic noise and could also contribute to lowering the noise pollution. The experts from Italy and ISO supported this proposal. The expert from France underlined that the whole text should be revised to update the test methods and that the limit proposed by OICA should be discussed. GRB agreed to resume discussion on this issue and requested the secretariat to distribute GRB-59-06-Rev.1 with an official symbol at its September 2014 session.