39. GRSG agreed to defer discussion on ECE/TRANS/WP.29/GRSG/2023/5, tabled by the expert from the International Association of the Body and Trailer Building Industry (CLCCR) to its October 2023 session.

32. The experts from CLCCR and CLEPA introduced GRSG-124-12 superseding ECE/TRANS/WP.29/GRSG/2022/17, to clarify the definition of a trailer/semi-trailer in case one or more trailer axles may be driven by a propulsion type integrated into the trailer (e.g. electric engine) in combination with the motor vehicle. The expert from the Netherlands expressed a study reservation on the proposal and recommended that parallel amendments be introduced in other UN Regulations such as UN Regulation No. 13 (Heavy vehicle braking). At the same time, he recalled to GRSG that UN Regulation No. 100 does not apply to trailer categories O₃ and O₄. GRSG agreed to resume discussion at its March 2023 session and requested the secretariat to distribute GRSG-124-12 with an official symbol.

56. The expert from CLCCR introduced ECE/TRANS/WP.29/GRSG/2022/17 to amend the consolidated Resolution on the Construction of Vehicles (R.E.3) by clarifying the definition of a trailer/semi-trailer in case one or more trailer axles may be driven by a propulsion type integrated into the trailer (e.g. electric engine) in combination with the motor vehicle. The expert from United Kingdom remarked on an inconsistency in the text of the proposal between the contribution to the propelling forces of the vehicle combination at all speeds and the speed limit of 15 km/h. The expert from the Netherlands added that amending R.E.3. and Special Resolution No. 1 (S.R.1) would be just a first step because a number of UN Regulations also need amendment (e.g. UN Regulations Nos. 13, 55 and 100) to allow for the introduction of such semi-trailers and full-trailers.

57. Finally, GRSG agreed to resume discussion on this subject at its October 2022 session on the basis of a revised proposal superseding ECE/TRANS/WP.29/GRSG/2022/17.