Proposal to update and clarify the regulation. The proposal refines definitions, removes the “AWD” abbeviation for “audible warning device” to avoid confusion with its more common use for “all wheel drive”, adds T category agricultural vehicles to the scope, modifies some administrative communications, and proposes three-direction acoustic measurements. The proposal also aims to structure the regulation to enable its application to additional sound warning devices not presently regulated at the international level, excluding acoustic vehicle alerting systems (AVAS) which will be subject to a separate regulation on minimum vehicle sound levels.

This proposal was made after consultations with OICA in order to provide for consistency in terminology used and to match the drawing in Annex 4 with the modified
provisions. The added word “warning“ is underlined.

Comments on the draft Supplement 5 to UN R28.

Proposals to modify the draft Supplement 5 to UN R28:

On new para. 14.3.6.: editorial clarification. (The purpose of fixing the height should be restricted for taking measurement in a particular test.)

On para. 6.2.1.1. and para. 6.2.1.3.: Since sound level meters on the market don’t meet the latest standard yet, IMMA proposes to use same IEC standard as in ECE R51.03: IEC 61672-1:2002.