Proposal to clarify the text of the regulation, update provisions in line with Supplement 1 to the 02 series of amendments (WP.29/2015/64), and to align its provisions with those of UN R41 and R51, including:

1. replace the term “two wheeled moped” with “L₁ category vehicle”;
2. replace the term “moped” with “vehicle”;
3. replace the term “noise” by “sound” except for its use related to background noise;
4. replace “noise made by” with “sound emitted by”;
5. specify in each use of the term “speed” whether the reference is to engine speed or vehicle speed;
6. add definition for “rated engine speed” in addition to “rated maximum net power”;
7. add definitions for “reference mass” and “test mass”;
8. add definition for “maximum vehicle speed”;
9. add the words “or electronically” and “rider selectable” to paragraph 6.3.2. to cover electronically adjustable exhaust or silencing systems;
10. allow the use of in-motion testing in addition to stationary testing in Annex 1 and add the necessary data reporting provisions in Annex 3 similar to provisions under UN R41 04 series;
11. update references to ISO standards; and
12. add sub-paragraphs to Annex 3, paragraph 5.2. to hinder tampering.

Proposal to exclude pure electric vehicles, including vehicles with auxiliary electric propulsion, from the scope of the regulation. This proposal has been submitted to complement WP.29/2017/4.

Discussion of motorcycle and related vehicle noise issues, especially related to aftermarket modification (non-original replacement exhaust silencer systems (NORESS)).

Presentation on the status of the European Commission-sponsored study to investigate the potential of and develop a proposal for new sound limits of L-category vehicles under Euro 5.