The CLIV informal group held its 15th session in Seoul from 24–27 March 2026, focusing on drafting performance requirements for buses and coaches. Japan proposed a five-minute inspection duration for drivers to confirm all children have disembarked; however, OICA suggested linking inspection time to passenger capacity. On Day 3, Japan presented a revised position: buses with 25 or more passenger seats require five minutes before a CLIV warning event occurs, while buses with fewer than 25 passenger seats require three minutes. All delegates supported this approach. The IWG agreed to draft papers for submission to affected GRs concerning external audible and visual warning signal proposals and intends to submit the draft UN Regulation to GRSP for informal consideration at the June 2026 GRSP session.