Proposal for acceleration calculation based on GNSS data to amend document GRBP/2025/27.

A version showing the changes is also available.

A version with tracked changes is also available.

Procedure for Demonstrating Equivalence of Vehicle Test and Indoor Drum Test Facilities for Tyre Abrasion and Determining the Transfer Function for Indoor Drum Test Facilities

Guidance document on the Procedure for Demonstrating Equivalence of Vehicle Test and Indoor Drum Test Facilities for Tyre Abrasion and Determining the Transfer Function for Indoor Drum Test Facilities

The secretary reported on C1 tyre testing activities. The Netherlands and Germany noted potential delays in Normal tyre testing at high temperature by end of March due to temperature conditions. The co-chair presented a status report for GRBP’s 83rd session, which the group approved. Future meetings are scheduled for February through April.

The GOIE on Tyre Noise Level Alignment in UN R117 targets reducing dispersion of measurements for tyres of Class C1 and C2 and investigating possibility to develop a test method with an SRTT as reference. An intermediate report will be presented to GRBP in September 2026, with a Working Document proposing evolution of the test method by September 2027. Five meetings have been held with 13 test centres from France, Japan, Netherlands, Spain and ETRTO. Eight of thirteen test centres have completed tests on 15 C1 and 5 C2 Japanese market tyres, with completion targeted for mid-2026.

Proposal to supersede the text for a Supplement 22 presented in document GRBP/2026/8.

Proposal to amend paragraph 2.18. to update Standard Reference Test Tyre definitions to ASTM International standards: E1136-19 for SRTT14, F2493-24 for SRTT16, F2872-25 for SRTT16C, F2871-25 for SRTT19.5, F2870-23 for SRTT22.5, F3678-25 for SRTT19.5 siped, and F3677-23 for SRTT22.5 siped. Also amend paragraph 12.21. to accept existing type approvals and grant extensions to class C₃ tyres using either SRTT19.5 or SRTT22.5 before 1 September 2028, and use SRTT19.5 siped or SRTT22.

Proposal to ensure robust tyre abrasion measurements regardless of the test method used.

Proposal to supersede document GRBP/2025/27 for a new UN Regulation on uniform provisions concerning the approval of tyres with regard to abrasion performance. The regulation establishes scope, definitions, application requirements, marking standards, approval procedures, and technical requirements for class C₁ tyres. It excludes temporary-use spare tyres, competition tyres, ice grip tyres, studded tyres, and certain other tyre categories. Type approval is granted if candidate tyres meet abrasion performance limits measured by one of two methods: vehicle testing on public open roads or indoor drum testing. Abrasion index limits are defined for normal, snow, and special use tyres, with adjustments for specific tyre groups. Requirements include conformity of production verification, penalties for non-conformity, and transitional provisions establishing Stage 1 and Stage 2 implementation timelines with specified dates for mandatory approval.

Proposal superseding GRBP/2026/7 to amend paragraph 1. of UN R75 to restructure the scope provision, clarifying that the Regulation applies to new pneumatic tyres designed primarily for vehicles of category L₁, and to exclude approvals for tyre types designed exclusively for “off road” use marked “NHS”, for competitions, and for bicycle rims according to ISO 5775-2:2021.

ETRTO measurement uncertainties reduction efforts for UN R117 rolling sound emission test methods are progressing through outdoor and indoor Round Robin tests. Eight of thirteen outdoor test centres have completed tests for C₁ and C₂ tyres; remaining centres anticipate completion by mid-year. Indoors, two of six ETRTO test centres completed tests with others expected finished by mid-year. An intermediate report with available data will be presented in September 2026, full results postponed to February 2027, and the Working Document with test method evolution now expected in September 2027 instead of February 2027.

Proposal to amend GRBP/2025/27 based on GRBP-83-32. Modifications to Annex 3 revise the abrasion index calculation methods for both vehicle test and indoor drum test methods. The abrasion margin (Amargin) is redefined in two stages accounting for evolution of measurement methods and tyre technology, with different values for normal, snow, and special use tyre categories. Amargin allowances for specific tyre groups, including severe snow conditions tyres, reinforced tyres, and tyres with nominal aspect ratio ≤40, are defined as cumulative additions to the base Amargin value.

ETRTO presents a temporary conservative transfer function for tyre abrasion testing with a gain value of 1.5, designed to minimize drum inversion risk and reduce rejection risk while enabling coexistence of Indoor Drum Method and Outdoor Vehicle method at GRBP 83rd session. The transfer function, based on TA-40-2 data analysis, will be revised following a 2026 workplan before a more relevant solution in Supplement 1 to UNRxxx at GRBP 84th session.

Proposal to supersede GRBP/2025/28, consolidating amendment proposals from GRBP/2025/28, GRBP-82-27, GRBP/2026/6, and GRBP-83-20-Rev.2. Changes include moving tyre abrasion provisions to a separate UN Regulation, deleting paragraphs 5.7 to 5.10 and Annex 10, updating ASTM standard references to F2872-25, F2871-25, and F3678-25, amending Annex 5 part (b) paragraph 1.1.1., and deleting paragraph 2.21. defining abrasion performance terms.

ETRTO presents its position on remaining open points for C₁ tyre abrasion limit settings, reminding positions from GRBP-82-24. Key points include: inclusion of two assessment methods; limit settings proposing approximately 23% market removal by Euro7 application timeline and additional 13.5% removal five years later; exclusion of C₁ special use tyres representing 0.7% of EU market; retention of 0.1 allowance for Extra Load tyres and tyres with nominal aspect ratio 40 suitable for speeds 300 km/h representing 7.2% of market. ETRTO views this as a challenging compromise package respecting political expectations and industry effort.

Proposal to establish a list of test facilities deemed equivalent pursuant to paragraph 12.8 of the draft UN Regulation on tyre abrasion. The list recognizes six foundational facilities that participated in the initial inter-facility campaign to develop abrasion limits for C₁ tyres. The facilities are: DEKRA Test Center SA (France, circuit); IFV (Germany, circuit); Link Engineering Company GmbH (Germany, circuit); Bridgestone Corporation (Japan, indoor drum); Sumitomo Rubber Industries, LTD. (Japan, indoor drum); and The Yokohama Rubber Co., Ltd. (Japan, indoor drum). These facilities generated foundational data used to define abrasion limits and are deemed equivalent for equivalence procedures under Annex 4.

Proposal to amend Annex 5, part (B) of UN R117. Changes include replacing “Average Deceleration (AD)” with “braking force coefficient (BFC)” terminology throughout paragraphs 2.2.2.1., 2.2.2.7.1., 2.2.2.7.2., and 2.2.2.7.3. Paragraph 2.2.2.3. is amended to clarify terminology regarding vertical static test load and load capacity. Paragraph 2.2.2.7.4. is deleted. Paragraphs 2.2.2.7.5. through 2.2.2.8.4. are renumbered and amended to align the wet grip test method for C2 and C3 tyres with changes made to the passenger car test method and ISO 15222:2025.

The document establishes procedures for demonstrating equivalence between vehicle circuit and indoor drum test facilities. It defines requirements for selecting exercise tyres and participating facilities, establishing baseline values from multiple facilities, and comparing facility results against baselines. For indoor drum facilities, transfer functions mathematically relate drum results to vehicle results, either as generic (fixed coefficient) or specific (facility-determined coefficient). Facilities must meet statistical criteria including result deviation limits and root mean square deviation thresholds to demonstrate equivalence.

Proposal to amend document GRBP-83-32-Rev.1. Paragraph 1.2.9. amended to exclude special use Professional off-road tyres from scope. Paragraph 2.51. amended to read that the authority which has granted type approval may verify conformity control methods, with normal minimum frequency of verifications at least once every three years. Justification states special use tyres should be excluded as no limits will be established for them, and the three-year frequency aligns with Schedule 1 of the 1958 Agreement.

ETRTO comments on EC/JRC compromise proposal for Annex 4 tyre abrasion. ETRTO proposes an ALI range minimum of 0.5 as feasible and consistent with statistical distribution in MA results, rejecting the 0.7 range as unrealistic. For Generic Transfer Function gain, ETRTO recommends retaining a = 1.38 rather than the revised a = 1.45, to minimize rejection of good vehicle test results. ETRTO requests TFTA ToR amendment to confirm these conditions by February 2027 based on TA-45-9.

Proposal to amend document GRBP-83-32-Rev.1 to renumber Paragraph 6.1. as 6.1.1., renumber current Paragraph 6.1.1. as 6.1.2., introduce new paragraph 1.4. to Annex 3 Introduction, amend paragraph 2.8. with detailed abrasion index and level calculation equations, renumber items in Appendix 2, delete item 1.3. from Appendix 2, and amend item 1.3. in Appendix 6 to clarify transfer function applicability between circuit and drum test facilities.

Proposal to amend GRBP-83-32-Rev.1 to ensure robust tyre abrasion measurements regardless of test method used. Amendments modify paragraph 6.1 to require test facilities demonstrate equivalence per Annex 4 procedure; insert paragraphs 12.8 and 12.9 deeming inter-facility campaign participants equivalent for C₁ tyres and allowing pre-regulation test data through 1 July 2028; insert Annex 3 paragraph 1.4 requiring inter-facility equivalence assessment; amend Annex 3 paragraph 2.8 with abrasion calculation equations including transfer function coefficient; insert test report items 1.1–1.4 in Appendices 2 and 6; and insert new Annex 4 establishing equivalence demonstration procedure for vehicle and indoor drum test facilities.

JATMA submitted this position on the draft UN Regulation for tyre abrasion at GRBP-83-54. JATMA requests adoption of the indoor drum test method under conditions equivalent to the vehicle test method for type approval. JATMA proposes that the Generic transfer function coefficient should be 1.14, calculated excluding tyre code 127 which exhibits significant variation. JATMA also proposes that the abrasion index range for tyres used in the Annex 4 procedure should be set between 0.4 and 0.5, and that no restrictions should be imposed on baseline test facilities when applying the Specific Transfer Function.

This status report documents the Tyre Abrasion Task Force’s progress toward finalizing a draft UN Regulation on tyre abrasion for C1 tyres, as presented to GRBP 83 Part II. The task force pursued three workstreams: data analysis to reduce method uncertainty and inversion risk, editorial improvements to increase clarity of the draft regulation, and development of a method equivalence solution. GRBP 83 Part I achieved consensus on limit values and introductory dates but could not reach consensus on equivalence procedures between convoy and drum methods. Six informal documents (GRBP-83-32-Rev.1, GRBP-83-48-Rev.1, GRBP-83-49, GRBP-83-50-Rev.1, GRBP-83-53, and GRBP-83-55) addressing equivalence methodology, drum specifications, and code of practice frequency were submitted for potential adoption at the extraordinary GRBP 83 Part II session.

The 50th IWVTA IWG session discussed strategies to increase IWVTA awareness and use, including harmonizing U-IWVTA with Japan’s Type Designation System and holding a workshop on July 17. Members reviewed UN R0/09 series amendments, considered revisions to General Guidelines on Transitional Provisions to prevent contradictions between series, and proposed a mechanism to identify compliance levels of UN type-approvals in DETA. The group will submit amended proposals to WP.29 in June and review updated Terms of Reference.

Proposal to delete Table of contents, Annex 10 and all its appendices, amend para. 1.1. to clarify application to new pneumatic tyres of classes C1, C2 and C3 in new state regarding sound emissions and rolling resistance and in new and worn state regarding wet adhesion, delete para. 1.3., amend para. 2.18. to specify reference tyres F2872-25, F2871-25, F3678-25 and F3677-23, delete para. 2.21., delete para. 3.1.1.1., amend para. 3.2.1. to describe major features and their effects on tyre performance, delete paras. 5.7. to 5.10., delete Annex 1 items 8.6. and 8.6.1., amend Annex 5 part (b) para. 1.1.1. to establish surface friction values by trailer or vehicle method according to tyre class and SRTT, amend Annex 5 part (b) para. 1.1.1.1. regarding coefficient of variation and peak braking force coefficient, and delete Annex 10. Document based on GRBP/2025/28, GRBP-82-27, GRBP/2026/6, GRBP-83-20-Rev.2 and GRBP-83-48-Rev.1.

The proposal adds Annex 5 on special provisions for testing vehicles equipped with an Automated Driving System (ADS) and adds definitions for ADS, Dynamic Driving Task, Category X and Y vehicles, logical signal, and Vehicle Master Control Switch. Amendments modify run-flat warning system requirements, braking performance tests, and tyre detection procedures to accommodate ADS-equipped vehicles.

Proposal to amend paragraph 1 (Scope) to clarify that the Regulation applies to new pneumatic tyres designed primarily for vehicles of category L₁, and to specify that approvals shall not be granted to tyre types designed exclusively for off-road use marked “NHS”, for competitions, or for bicycle rims according to ISO 5775-2:2021.

Proposal to amend paragraph 1.1. to specify that UN R106 applies to new pneumatic tyres designed primarily for agricultural and forestry vehicles in categories T, R and S; amend paragraph 1.1. footnotes to include definitions; and amend paragraph 3.1.5.3. to address marking requirements for implement tyres for mixed applications of speed category symbol D or E where service descriptions for trailer and traction applications are equal.

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.

The 51st session of the IWVTA Informal Group is scheduled for June 17, 2026, at 14:00 (CEST) in Flensburg as a hybrid meeting. The agenda includes adoption of the agenda and report of the 50th meeting, highlights from the 198th WP.29 session, consideration of UN R0/09 series of amendments with Annex 4 update, proposed amendments to Guidelines on Transitional Provisions, discussion of boosting IWVTA awareness and promotion, extension of mandates beyond November 2026 with proposed terms of reference, and any other business, with a future meeting proposed for November 12 in Paris.

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.

Proposal to amend the General Guidelines for United Nations regulatory procedures and transitional provisions in UN Regulations based on WP.29/2024/76, to move transitional provisions applicable to all series of amendments to the beginning of transitional provisions sections, retitle successive series provisions as “Transitional provisions for the XX Series” and “Transitional provisions for the XX+1 Series”, add footnote reference 6 to para. V.3, and correct terminology from “previous” to “preceding” in footnotes 4–6 for consistency.

The Informal Working Group on International Whole Vehicle Type Approval assists WP.29 in harmonizing vehicle regulations under the 1958 Agreement. It clarifies issues related to UN Regulation No.0 and General Guidelines on Transitional provisions, upgrades UN Regulations applicable to IWVTA annually, and submits amendment proposals to WP.29 each November. Short to mid-term objectives include proposing user-friendly U-IWVTA and packaged L-IWVTA by end of 2029. Long-term objectives involve submitting proposals for full IWVTA covering all necessary UN Regulations. The group operates under WP.29 supervision, is open to 1958 Agreement Contracting Parties and NGOs, and makes decisions by consensus.

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.