Proposal to amend UN Regulation No. 179 to include testing of vehicles with limited speed. The document specifies amendments to the laboratory measurement of brake emissions for light-duty vehicles, including provisions for vehicles with a maximum speed lower than the maximum speed of the Base cycle. These vehicles may be part of the same brake corner emissions family as vehicles suitable for the Base cycle, with their emission factor calculated based on the parent family’s reference PM and PN emissions according to equations 7.1, 7.2 and 7.3. At the manufacturer’s request and with approval authority agreement, such limited-speed vehicles may be assigned to a specific family using the adjusted cycle described in Appendix 3 of Annex 4, with the same changes to be applied to UN GTR No. 24.