Informal meetings are scheduled in conjunction with the GRBP session from 31 August to 4 September 2026. The IWG RD-ASEP Workshop runs in two parts on 31 August and 1 September in Concordia 5 and H.207, in-person only and hybrid respectively. The Task Force – Vehicle Sound meets on 1 September in H.207 in hybrid format. The Working Party on Noise and Tyre holds its 84th session on 2, 3, and 4 September in Room XI in-person only. All meetings are located at Palais des Nations. Interpretation services in English, French and Russian are provided from Wednesday morning to Friday evening in Room XI.

The IWG RD-ASEP Informal Group is developing a mandatory test procedure for UN R51 to assess vehicle noise emission compliance under conditions other than Annex 3, ensuring no defeat device schemes exist. The Editing Task Force created a consolidated R51.04 draft incorporating Supplements up to Supplement 11, with mandatory random RD-ASEP testing for approval and revised control ranges. R51.04 RD-ASEP expands vehicle speed range to 1-100 km/h, adds vehicle performance criteria, implements random test points, and requires testing for approval. Working document submission is expected September 2027, with expected adoption February 2028.

Proposal to amend UN R51 in the 04 series of amendments based on GRBP-84-07, adding definitions and specifications for Real Driving Additional Sound Emission Provisions applying to vehicles of categories M₁ and N₁, modifying sound measurement methods and test procedures including indoor testing provisions, establishing a sound expectation model for RD-ASEP compliance evaluation, introducing provisions for vehicles equipped with an Automated Driving System, and updating Annexes 3 through 10 and associated appendices with revised test conditions, gear selection flowcharts, temperature and test-track corrections, tyre rolling sound measurement procedures, compressed air noise assessment, and conformity of production checks. No Contracting Party shall refuse to grant type-approvals under the 04 series of amendments from its entry into force until [TBD date], after which approvals under the preceding 03 series may no longer be accepted.

Proposal for Supplement 3 to the original version of UN Regulation No. 172 to amend para. 1.1. to clarify that this Regulation applies to retreaded pneumatic tyres of Classes C1, C2 and C3 with regard to their snow performance and for C2 and C3 tyres with regards to their classification as traction tyre, and insert new para. 1.2. to state that Contracting Parties shall issue or accept approvals to snow performance of retreaded tyres of classes C1, C2 and C3 and/or the classification as traction tyres for retreaded tyres of classes C2 and C3.

Proposal to amend para. 1.1. to clarify that retreaded pneumatic tyres of Classes C₁, C₂ and C₃ are subject to snow performance requirements and C₂ and C₃ tyres to traction tyre classification, and insert new para. 1.2. to establish that Contracting Parties shall issue or accept approvals to snow performance of retreaded tyres of Classes C₁, C₂ and C₃ and/or the classification as traction tyres for retreaded tyres of Classes C₂ and C₃.

Proposal to amend Annex 7, paragraph 3.1, to add provisions allowing discard of test runs when additional operating conditions lead to riding conditions not expected to occur in real traffic such as front wheel lift up, apparent wheel spin, chain slap, or engine lugging, and amend paragraph 3.2.2 to specify that if unusual riding conditions occur during testing, the test shall be performed in the next higher gear and maximum vehicle speed shall be reached at line BB’ instead, thereby ensuring consistency with the 05 and 06 series of UN Regulation No. 41.

The UN IWG for CLIV is in Phase 2 on developing a new UN Regulation on Children Left in Vehicles (CLIVs) for vehicle categories M2 and M3. The draft UN Regulation includes requirements with regards to visual and audible external warnings in buses and coaches to assist in the prevention of children being left inside. The IWG has prioritized the development of a new UN Regulation for buses and coaches in the first instance.

Proposals for earlier series of amendments those may be used in certain country
where R156-01 is required. The provisions regarding provision of information on hardware and software relevant to approval testing are moved to the section related to specifications and/or tests as instructed in R.E.3. and the amendment made by WP29-197-06 is reflected.

Proposal for a Guideline regarding the Interpretation of Paragraph 6.2.3. ASEP in the 03 series of amendments to UN Regulation No. 51, updating Informal Document GRB-68-03 and based on GRB/2005/5 and GRB/2010/9. Part A addresses internal combustion and hybrid vehicles when the combustion engine is operating, defining typical on-road driving as vehicle speeds between 15 km/h and 100 km/h, accelerations not exceeding 2 m/s² and vehicle performance not exceeding 35 m/s², and engine speeds of at least 1.5 times idle speed and not exceeding the maximum outlined in Annex 7. Significant deviation means sound level exceeding reference values by at least 6 dB(A). Type approval test results derive from Annex 3 or Annex 7 values, with reference values established using regression curves or calculation principles. Part B addresses electric and hybrid vehicles propelled electrically only, extending guidance to electrified vehicles and Enhanced Exterior Sound introduced by Supplement 11. Typical on-road driving for electric vehicles includes vehicle speeds greater than 0 km/h and up to 100 km/h and standstill covered by UN-R 138. Significant deviation for electric vehicles is at least 3–6 dB(A).

Proposal to solve the discrepancies between the test report format and the description of the test method for C2 and C3 tyres.

Proposal replaces the GRBP2026/26

Road legal race tyres are currently defined in the new UN R186 on abrasion but fall out of its scope. Considering that the new UN R186 on abrasion applies only to tyres that conform to UN Regulation No. 117., it is proposed to replicate therein the definition, the marking and the requirements of road legal race tyres by adding the new paragraphs 2.21., 4.5. and 6.9.

Proposal to improve the readability of the text by using only the wording “run flat tyre”, mentioning the alternative wording “self supporting tyre” in a note and restricts the use of ZR and ZRF marking to the tyres suitable for speeds greater than 300 km/h.

Proposal introduces the definition of “dual fitment” which is missing in the current text and improves the readability of the text by using only the wording “dual fitment”, mentioning the alternative wording “twin fitment” in a note.
Solves problem of type approving LT tyres with load-capacity index greater than or equal to 122 and suitable for dual fitment.

Proposal to improve the readability of the text by using only the wording “run flat tyre”, mentioning the alternative wording “ self supporting tyre” in a note.

Proposal to clarify that an extended mobility tyre shall not be retreaded without being marked with the EMT symbol to avoid the mix up on the same axle with a tyre of radial structure not featuring extended mobility capabilities

Existing transitional provisions do not address the issue of retreaded tyres produced in accordance with the applicable requirements before 1 September 2028. Thus, a significant quantity of retreaded tyres will stay stocked within the different stages of the distribution channels.

Introduce the definition of “dual fitment”

Updates the year reference to the latest international standard specifications

Progress Report (February 2026 – September 2026)
Conclusion of work on UN Regulation on tyre abrasion for C1 tyres, launch of C2 work, outlook for C3 work

Proposal to amend UN Regulation No. 142 to clarify that a maximum speed warning label specifying the lowest value of the maximum speed capability of fitted snow tyres displayed inside the vehicle in a prominent position readily and permanently visible to the driver can be via a permanent physical label or an electronic display, and in case of an electronic display the warning can be shown permanently or when the respective speed limit is approached, reached or exceeded, and to provide that the speed warning label shall not be required for vehicles of categories X and Y equipped with an ADS.

Proposal to amend para. 6.2.1.1. to permit testing of vehicle sound either indoors or outdoors with equivalent results, add new Annex 11 specifying indoor testing provisions, amend Annex 1 to insert para. 8.5. and 8.5.1. requiring documentation of test method selected, amend Annex 3 para. 1. to specify sound level meter requirements for indoor testing per IEC 651 and IEC 61672-3, amend Annex 3 para. 1.1.1. to provide calibration procedures for indoor testing per IEC 942:1988, amend Annex 3 para. 1.3. to exempt wind speed monitoring for indoor facilities, amend Annex 3 para. 2.1. and add para. 2.1.4. to specify outdoor and indoor test site requirements per ISO 362-3:2022 and ISO 26101, add para. 2.1.5. specifying indoor ambient conditions, add para. 2.2.7. addressing test mass for indoor dynamometer testing, amend Annex 3 para. 3. to specify outdoor and indoor test procedures per ISO 362-3:2022 Variant A, amend Annex 3 para. 3.1.1. to clarify outdoor testing microphone placement, add para. 3.1.1.4. defining virtual lines and simulated vehicle speeds for indoor testing, and renumber former paras. 3.1.1.4. and 3.1.1.5. as 3.1.1.5. and 3.1.1.6.

Rationale for Figure Part B.5 of GRBP-84-36-Rev.1