Proposal to introduce a procedure and thresholds on wet grip performance for C1 tyres in worn state.
ECE/TRANS/WP.29/GRBP/72, para. 23 and ECE/TRANS/WP.29/GRBP/73, based on GRBP-74-33-Rev.1, ECE/TRANS/WP.29/GRBP/2021/17 as amended by GRBP-74-31-Rev.1 and GRBP-75-25-Rev.1.