Proposal to amend para. 2.2.2.4. to include electric regenerative braking system and electric propulsion system, amend para. 2.21. to define Electric Regenerative Braking (ERB), add para. 2.56. to define e-trailer, amend para. 5.2.2.7. regarding braking surface connection and electrical regenerative braking system disconnection, insert para. 5.2.2.26. establishing special requirements for e-trailers and trailers equipped with ERB of Category O₃ or O₄, insert Annex 4 paras. 1.7.1.3., 3.1.2.6., and 3.1.3.5. requiring ERB system deactivation during brake applications and tests, insert Annex 13 para. 4.7. requiring anti-lock braking system for vehicles with ERB, and amend Annex 16 tables to include trailer regenerative system parameters, based on GRVA/2025/15.

Proposal to establish definitions for “e-axle”, “e-axle trailer” and “dynamo function” and to establish provisions for the approval of e-axle trailers with regard to their “dynamo function”.

This document proposes amendments to UN Regulation 13 for trailers with dynamo function, superseding GRVA-22-26, GRVA-2025-15, and GRVA-21-12. The dynamo function converts vehicle kinetic energy into electrical energy without affecting braking system forces and is limited to trailers of category O₂, O₃, and O₄ pending further development. Maximum retardation power limits are 22 kW for O₃/O₄ trailers and 2 kW for O₂ trailers, measured using specified methods. Requirements include wheel locking prevention with braking rate not exceeding 0.04 per wheel, functional safety assessment per Annex 18, and demonstration that anti-lock and stability control systems comply when dynamo function is enabled. The dynamo function shall not be used during brake application testing. Administrative amendments update Annexes 2, 4, 5, 10, 19, 20, and 21 to reference e-axles and dynamo functions.

Proposal for withdrawal based on to highlight the broader implications for vehicle design and usability for consumers resulting from this proposal. The lowering of the sideguard and reduction in ramp angle will give reduced flexibility for vehicles and trailer combinations in certain applications (i.e. loading roll-
on, roll-off vessels) and conflict with the road surface and local infrastructure (i.e. grounding out), which will lead to damage or reduced life of sideguards.