Proposal to:

1. Clarify that the “supplier of the tread used for the retreading process” is responsible for conformity of production of the
   supplied tread,
2. Align the classification “traction tyre” with UN R117
3. Provide transitional provisions to manage the switch from the requirements given in paragraph 6.2.1. to the ones given in the paragraph 6.2.2.,
4. Correct the omission of provisions for “professional off-road tyre” and their alignment with UN R30,/li>
5. Correct a reference to “Appendix 1” of the 1958 Agreement to “Schedule 1”, and
6. Manage the transition to the new standard reference test tyres (SRTTs)
   19.5 and 22.5 siped

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.