Proposal to clarify that the use of any braking system control for testing the effectiveness of the secondary braking system in failure conditions is allowed.

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”.

Proposal from OICA, CLEPA, and CITA to amend CITA’s proposal to enable real-time reading of electrical transmission brake demand values via an electronic vehicle interface and an off-board electronic device during periodical technical inspections, including a 24-month transitional period.

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 to clarify that the parking brake may be actuated while the vehicle is in motion via actuation of the vehicle’s service braking system by means of an auxiliary control which could be an Electronic Parking Brake (EPB) and to promote consistent interpretation of the activation conditions for an Emergency Stop Signal (ESS), including by application of the service braking system via the EPB control.

The e-Trailer Industry Group reports on discussions regarding electrically propelled and recuperating trailers. ISO 11992-2 Edition 4 is not safely implementable due to incompatibility with current UN regulations, missing PGNs, and risks of malfunction. ISO/TC 22/SC 31/WG 4 launched Edition 5, targeting publication in early 2027. Amendments to UN R13 and UN R100 are being developed in phases, with Phase 1 addressing trailer dynamo function and Phase 2 addressing e-axle trailers. Two workshops with Contracting Parties are planned to establish shared understanding and develop concrete parameter extensions for amending UN Regulations.

Proposal to delete paragraph 1.2.6. excluding e-axle trailers with e-axles providing electric propulsion and/or incorporating an electric regenerative braking system from the scope of UN R13, and add definitions of “e-axle,” “e-axle trailer,” “dynamo function,” and “e-trailer”; add special requirements for power-driven vehicles supporting e-trailer operation, e-axle trailers equipped with dynamo function, and e-trailers of category O; add requirements for electric control lines conforming to ISO 11992-2:²⁰²⁷; specify message support and functional compatibility; and add provisions for electric regenerative braking, dynamo function, and propulsion, including parameters such as retarder torque demand priority, propulsion force limits, overriding mode activation at speeds below 15km/h, and vehicle stability function interaction.

Proposal to introduce provisions for approving single vehicles involved in modular vehicle combinations, e.g. towing trailers, “road trains”.

Proposal to introduce requirements for endurance braking systems for vehicles equipped with an electric regenerative endurance braking system.

Proposal to clarify provisions regarding the actuation of the parking brake warning device to cover the case of electric control transmission systems where there may be a transition between parked (applied) and un-parked (released) braking states. The aim is to reduce risks of user confusion by specifying that the warning device would be actuated only after the parking brake has achieved a stable applied state.

Proposal to permit the use of a positive lock type system as an alternative to a friction type parking brake system.

Proposal to clarify provisions concerning the type-IIA test and the test mass of vehicles authorized to tow trailer(s) (responding to the proposal made in document GRVA/2024/7).

Proposal for provisions to enable the use of approval of a park lock device as an alternative to the friction parking braking to hold the vehicle.

Proposal to enable the type approval of a park lock device as an alternative to, or in combination with the friction parking braking to hold the vehicle.

Proposal to introduce provisions for the approval braking systems for e-trailers and Electric Regenerative Braking (ERB) in towed vehicles of Category O.

Proposal to clarify that only one braking control (e.g., service braking control, parking brake control) shall be used for each test condition of the secondary braking effectiveness and to permit the selection of the braking control based on the vehicle load condition.

OICA proposal to amend the parking brake provisions of the 2009 draft proposal to amend Regulation No. 13 to specify uniform requirements for towing trailers and motor vehicles which may tow more than one trailer (road train combinations). This earlier draft proposal has been taken up as the basis for work by the Modular Vehicle Combinations informal group.

Proposed changes to align RxSWIN provisions with the RxSWIN template adopted through WP.29-197-06, remove the proposed requirement to comply with UN R156/01 or later from R157 and R171, remove amendments to UN R155 as decided by the IWG CS/OTA, apply the RxSWIN amendments also to earlier series of amendments in R13, R13-H, R79, R131, R152, R157, and R171, update references to the latest version of R.E.3, ECE/TRANS/WP.29/78/Rev.8, in earlier series, and correct paragraph references and improve structure in R89, R139, R140, R155, R156, and R171.