Proposal to revise the definition of principal grooves in paragraph 2.14.1.; delete paragraph 2.48. and renumber subsequent paragraphs; amend paragraph 2.51. regarding material supplier definition; revise paragraph 3.2.6. on M+S inscription requirements; modify paragraph 4.1.5.3.2. to include a table of tyres classified for severe snow conditions; delete paragraphs 4.1.5.3.2.1., 4.1.5.3.2.2., and 4.1.5.3.2.3.; revise paragraphs 6.5.3., 6.5.8., 6.6., 6.7.4., and 7.1.5. regarding material supplier requirements and diameter calculations.

Proposal to modify paragraph 2.4. to define “Material supplier,” delete paragraph 2.59., and renumber paragraphs 2.60., 2.61. and 2.61.1. as 2.59., 2.60. and 2.60.1., amend paragraphs 3.2.8., 3.6., and 4.1.5.3.2. regarding M+S markings and tyre classifications, and delete paragraphs 4.1.5.3.2.1., 4.1.5.3.2.2. and 4.1.5.3.2.

Proposal to amend UN R141 under section 2 to add definitions of Automated Driving System, Dynamic Driving Task, Category X vehicles, Category Y vehicles, Logical signal, and Vehicle Master Control Switch, amend under section 5 to update performance requirements and warning signal specifications for vehicles equipped with an ADS and towed vehicles, amend Annex 1 to add a vehicle ADS status field, amend Annex 3 regarding test procedures for TPMS including deactivation of TPRS and CTIS, amend Annex 4 regarding test weight and refill functionality checks, amend Annexes 5A and 6 regarding towed vehicle communication interfaces, and insert new Annex 9 containing special testing provisions for vehicles equipped with an ADS.

Proposal to amend paragraph 1, footnote 1, insert new paragraphs 2.23. to 2.26. defining Automated Driving System, Dynamic Driving Task, Category X vehicles, and Category Y vehicles, amend paragraph 4.4.1., footnote 2, amend section 5.2.3. to add requirements for vehicles equipped with an ADS and exclude speed warning label requirements for vehicles of categories X and Y, amend Annex 1, footnote 4, insert new item 6.2. regarding ADS equipment, insert new paragraph 2.2. in Annex 2 Section I regarding ADS equipment, and insert new paragraph 4.2. in the Addendum to communication form regarding brief description of the ADS if fitted.

Proposal for a new UN Regulation on the approval of new pneumatic tyres of class C₁ conforming to UN R117 with regard to their tyre abrasion performance, excluding temporary-use spare tyres, tyres with rim diameter ≤13 or ≥25, competition tyres, tyres for vehicles of categories other than M₁–M₃, N₁–N₃, O₁–O₄, ice grip tyres, studded tyres, speed category less than 120 km/h, special use tyres, and road legal race tyres. Abrasion index limits are 1.00 for normal and snow tyres, with adjustments for specific groups. Approval requires marking with approval reference number and suffix (A1 or A2). Testing uses either vehicle test method on public open roads (~8000 km) or indoor drum test method (5044 km), with test facilities demonstrating equivalence per Annex 4. From 1 July 2028, stage 1 approvals required for new types; from 30 June 2030, all types. From 1 July 2033, stage 2 approvals required for new types; from 30 June 2035, all types. Until 1 July 2028, test results from tests performed

Proposal to amend UN Regulation No. 172 based on GRBP/2026/10 as amended by GRBP-83-15-Rev.1. Amendments include revised definition of supplier of tread in paragraph 2.2.; modification of paragraph 6.2. to require tyres to meet conditions in paragraph 6.2.1. or 6.2.2.; insertion of new paragraphs 6.2.2., 6.2.2.1., 6.2.2.2., and 6.2.2.3. establishing calculation methods for deformation potential and number of traction elements based on tyre class and nominal rim diameter; insertion of new paragraph 6.4.(a) for class C₁ tyres; renumbering of former paragraphs 6.

Proposal to amend paragraph 2.2. to clarify the definition of “Supplier of the tread used for retreading process”; insert new subparagraph (a) in paragraph 6.4. establishing requirements for class C1 tyres; renumber former subparagraphs (a) and (b) as (b) and ©; replace “Appendix 1” with “Schedule 1” in paragraph 8.; amend paragraph 12.1. concerning type approvals as from 1 September 2030; amend paragraph 12.3. regarding acceptance of existing type approvals of class C3 tyres; and amend Annex 1 regarding communication of type approval for retreaded tyres.

Proposal to amend para. 2.18. to update Standard Reference Test Tyre definitions with ASTM International standards E1136 19, F2493 24, F2872 25, F2871 25, F2870 23, F3678 25, and F3677 23 for specified tyre sizes and designations, and amend para. 12.21. to permit Contracting Parties to continue accepting existing type approval and extensions to existing type approvals of class C3 tyres first granted before 1 September 2028 using SRTT19.5 or SRTT22.5, with SRTT19.5 siped or SRTT22.5 siped required for new tests performed on different representative tyre sizes for extensions granted after 01 September 2028.

The 47th session of the Task Force on Tyre Abrasion convened on 2 April 2026. The review committee prepared final consolidation of a new UN Regulation on Tyre Abrasion for WP.29. TFTA reviewed the workplan including data assessment, tyre batch use, and equivalence assessment governance. For C2, ETRTO presented findings on the vehicle test method at 10,000 km, while JASIC reported on indoor drum test development. Discussion on C3 Heavy-Duty Vehicle tyre applications was deferred. The next session is scheduled for 11 May 2026.

Results of the review of proposals for UN Regulations R28, R51, R64, R138, R141, R142, and R165 regarding autonomous vehicle readiness. Key findings include: inconsistent Mass in Running Order definitions between R51 and R138 versus RE3; unclear special testing provisions in R64, R138, and R165; need for clarification on ADS optical and logical signal transition in R64; redundant full definitions from RE3 in multiple proposals should reference RE3 via footnote instead; inconsistent ADS activity terminology across R64, R141, and R165 should be standardized; incorrect Category Y references in R51 Table 2; and definition and spelling errors in R51, R138, R141, and R165.

The agenda includes discussion of status of the work plan 2026 including the ITTAC proposal on tyre abrasion Convoy Method -Dual-Normalisation Framework (TA-45-08/Rev.1) and UTAC Tyre abrasion timeline Gantt (TA-46-03/Rev.1), development of the C1 tyre mileage potential metric and tread depth measurement prescription, and test method development status under C2 and C3.

ETRTO proposed three ways to estimate service life (TA-36-04): tread depth measurements, initial tread depth and abrasion index, and tread mass. JRC presented a service life index (TA-32-04) based on tread depth measurements and conducted a preliminary assessment of the second concept. Service life is estimated by linear extrapolation to 1.6 mm from tread measurements at test start and end. The Service life index is calculated as the ratio of candidate to reference tyre service life. Next steps include confirming the equation for service life via tyre characteristics and clarifying which tyre characteristics are needed.

TA-48-02 updates TA-47-02. C2 tyre abrasion rate index vehicle method uses a convoy of up to 4 vehicles with single tyres, GVW up to 3.5T, FWD, loaded 60%–74% of tyre nominal load with 50/50 front/rear distribution. Test distance is 10000 km at 80% nominal pressure. Reference tyres use 2 sets of test runs with C2 candidate SRTT and existing C1 SRTTs. 2025 testing in 235/65R16C and 205/65R16C sizes showed C2 tyres sensitivity to temperature similar to C1 tyres. 2026 plan repeats and extends 2025 testing to confirm reference tyres strategy, assess temperature sensitivity and pressure impact, and define validation plan.

The document presents a European heavy-duty vehicle and tyre market overview and C3 test method development status. The C3 tyre market is complex and diversified, with applications including long haul, regional, on/off road, winter, and urban use. A test concept has been developed focusing on road usage with 22.5" tyres, using convoys of up to four vehicles with defined acceleration standards, road distribution of 60% motorway and 40% regional roads, and tests per axle comparing candidate tyres to reference tyres. Current activities include assessment of reference tyres strategy, temperature sensitivity evaluation, and confirmation of test parameters for heavy trucks in N₃/O₃ configuration, with tests reaching 30,000 to 45,000 kilometres.

DEKRA Test Center examined whether vehicles fitted with SRTT impact tyre abrasion rates. Tests DEKRA #104 and DEKRA #41 compared SRTT Summer as candidate against SRTT Winter as reference, with abrasion indices of 1.18 and 1.19 respectively, showing no vehicle impact. Tests DEKRA 8 and DEKRA 9 showed abrasion rates of 45.1 mg/km/T and 45.0 mg/km/T respectively with no difference despite different vehicles. A 2024 convoy test with two Golf vehicles fitted with identical SRTT Summer showed a difference of 1 gram cumulated weight loss after 7,962 km (0.07 mg/km/T). DEKRA concludes the impact on abrasion level of the reference vehicle using SRTT is low or very low.

Existing C1 tyre-abrasion test methods cannot be directly applied to C3 tyres because vehicles equipped with C3 tyres are used differently. Japan is developing a vehicle test method using WHVC mode and plans to develop a drum test method based on test conditions and results. Test conditions will convert vehicle driving conditions representing the world into indoor drum test settings. C2 test method uses driving mode based on WLTP with fixed test load details, with verification tests using reference tyres. For C3, driving modes and test conditions are under preliminary investigation, with verification tests to be planned.

The agenda for the 74th session of the Informal Working Group on Wet Grip of Worn Tyres scheduled for May 19th, 2026, remotely via Teams. The agenda includes welcome and opening remarks, adoption of the agenda and minutes of the previous 73rd session meeting held 31 March 2026, discussion of the workplan 2025 for C1 tyres status test campaign, and determination of the next meeting date.

The Worn Tyres Post-Processing task force held its 34th session on 13 May 2026. Ninety-three percent of 3PMSF tests have been completed and members agreed to start the post-processing activity for the 3PMSF cluster. Test results for Normal tyres will be delivered once the high temperature range will be achieved. Future sessions are scheduled for 28 May, 15 June, 2 July, and 15 July 2026.

Proposal to insert new paras. 12.15. and 12.16. to establish transitional provisions, and amend Annex 4, Part A, Section I to update the list of requirements for U-IWVTA. Para. 12.15. provides that as from the official date of entry into force of the 09 series of amendments, no Contracting Party applying this UN Regulation shall refuse to grant or refuse to accept an IWVTA issued pursuant to this UN Regulation as amended by the 09 series of amendments. Para. 12.16. provides that as from 1 September 2027, Contracting Parties applying this UN Regulation shall not be obliged to accept type approvals to any of the preceding series of amendments, first issued after 1 September 2027. The amendment updates the table in Annex 4 to specify series of amendments for various UN Regulations including amendments to UN R14, UN R16, UN R46, UN R48, UN R79, UN R94, UN R95, UN R100, UN R110, UN R127, UN R129, UN R134, UN R137, UN R138, and UN R154.

The 73rd session of the Informal Working Group on Wet Grip of Worn Tyres convened remotely on 31 March 2026. The agenda and previous session minutes from 3 February 2026 were adopted. The WTPP secretary reported on testing activities status for the workplan stage 1 for C₁ tyres, with results to be presented to GRBP at its 84th session in September 2026. ETRTO stated conclusions can only be made on complete datasets. Future meetings are scheduled through July 2026.

The 1st DETA/IWVTA Joint Workshop is scheduled for June 17, 2026, 9:30–12:30 (CEST) as a hybrid meeting in Flensburg. The provisional agenda includes opening remarks from the DETA Chair, IWVTA Chair, and President of KBA. Part 1 covers DETA topics: what DETA is, a demonstration, ASEAN countries’ expectations, and ways to make DETA more attractive. Part 2 covers IWVTA topics: what IWVTA is, industry’s expectations, issuance and acceptance of IWVTA certificates in the EU, and ways to make IWVTA more attractive. The workshop concludes with any other business.

IWVTA is an internationally recognised whole vehicle type approval scheme within the revised 1958 Agreement framework. It establishes mutual recognition of vehicle type approvals at the whole vehicle level across Contracting Parties, eliminating requirements for further testing, documentation, or certification for safety, environment, energy, and anti-theft. IWVTA comprises two approaches: U-IWVTA applies the highest stringency of latest UN Regulations, while L-IWVTA permits omissions or lower stringency versions. The scope is limited to passenger cars. Merits include simplified type approval systems, reduced testing and administrative costs, and shortened processing times.

Draft minutes of the 74th session of the Informal Working Group WGWT held May 19th, 2026 (9:00–10:00 CET), remotely. Attendance per document WT-74-04. Agenda adopted. Previous meeting minutes of 73rd session (31 March 2026) not uploaded; to be adopted at next session per document WT-74-01. WTPP secretary updated on testing activities status per document WT-74-02. 3PMSF data from one test center pending before sharing anonymised data to WTPP for analysis. JASIC provided completed test data on 3PMSF and Normal tyres. Next meetings: WTPP 35 (28 May 09:00–10:30 CET); WTPP 36 (15 June 09:00–10:30 CET); 75th session (16 June 8:00–9:00 CET); WTPP 37 (02 July 09:00–10:30 CET); WTPP 38 (15 July 09:00–10:30 CET) per document WT-74-02.

• ETRTO to check feasibility to upload acceleration calculation examples on TFTA wiki,
• SWG on data assessment to define scope and mandate by 49th session,
• ITTAC proposal (TA-45-8v1) on Convoy Method Dual-Normalisation Framework deferred to next session,
• UTAC Gantt timeline reviewed; ETRTO regulatory experts reviewed proposal; technical experts review pending,
• Tyres Europe stated EU Tire Industry funded over 3m for C1 activities and will provide over 1m additional financing for C2 and C3 work; requested TFTA co-financing,
• EC will escalate request; JRC will participate with 2 convoys for C2 in 2026 and C3 in 2027,
• SWG on data assessment to define scope, mandate, and leader for next session,
• DEKRA presentation on vehicle impact with SRTT; vehicle effect neutralized through tyre rotation for correlation purposes,
• JRC service life update presented; analysis planned for end of 2026,
• ETRTO C2 test method development restarted May 2026; temperature impact observed for winter SRTT requiring 2026 workplan verification,
• GRBP Working Document delivery for C2 test method postponed to February 2027,
• ETRTO and JASIC C3 presentations deferred for comments next session.