IWG RD-ASEP status report to GRBP-83 after the 10th session in December 2025. Work on RD-ASEP for UN R51 is developing a mandatory procedure after the monitoring phase, while R41 work has concluded. The Data Analysis Task Force reported on database sufficiency, boundary conditions, CVT vehicle modelling, and potential inclusion of N₂/N₃/M₂/M₃ vehicles. An Editing Task Force created a consolidated R51.04 draft reviewed in December. IWG RD-ASEP recommends no monitoring requirements be approved without corresponding mechanisms to collect, analyze, and report results. M category/R51 informal document submission expected September 2026 and working document February 2027. L-category/R41 requires no further action.

IWG RD-ASEP is developing a mandatory procedure for UN R51 after the monitoring phase, with R41 work concluded. The Data Analysis Task Force reported in October 2025 on vehicle database sufficiency, boundary conditions, and CVT vehicle modeling. An Editing Task Force created a consolidated R51.04 draft reviewed in December 2025. IWG RD-ASEP recommends that no monitoring requirements be approved without corresponding mechanisms to collect, analyze, and report results. Submission targets shifted to September 2026 for informal document and February 2027 for working document due to database finalization and financial support needs.