UN R55 does not include provisions for minimum articulation angles of couplings. However, couplings may be damaged if a vehicle combination takes a narrow curve or other maneuver that exceeds the coupling design. In order to prevent coupling failures, this proposal suggests minimum articulation requirements based partly upon ISO 1726-1 and 11407 for drawbar and fifth wheel couplings.

Proposal under preparation for the GRRF by the R55 informal group. This proposal concerns a procedure to identify allowable combinations of performance values Dc and V for drawbar coupling equipment. This proposal would amend the Revision 2 proposal for UN R55.

Draft proposal under development within the R55 informal group.

Updated version of the draft consolidated revision of UN R55 following the 11th R55 informal group session.

Updated version of the text following the 11th R55 informal group session and highlighting the changes

Australia Road Research Board (ARRB) Internal Report related to ISO/TC22/SC15/WG4 N 535 Annex 5.

List of pending proposals for the update to UN R55 from GRRF participants.

The text reproduced below was prepared by the experts of the informal group on UN Regulation No. 55 and introduces amendments on:
a) Requirements on remote indication;
b) Availability of information on coupling fixing points for A50X couplings;
c) On lateral strength of drawbars;
d) Includes a new class definition for fully automatic drawbar couplings.

WABCO comments concerning communication between vehicles, power supply redimensioning, and vehicle stability requirements (including use of electronic vehicle stability control systems).

Australian research paper suggesting that an air-suspended tandem converter dolly could pitch significantly under braking as compared to mechanically suspended dollies.

History of discussions concerning the D-value on modular vehicles and combinations with more than one trailer.

Review of the development of ISO 12357-3.

Presentation to explain the historical background behind the work of ISO/TC22/SC15/WG4 and the UN R55 informal working group.

Revised drawings prepared for the informal working group amending the regulation.

E-mail communication between the WP.29 secretariat and the UN R55 revision informal group proposing the drafting of a new consolidated version of the amended regulation incorporating all the informal group changes.

Working draft of the comprehensive update to UN R55 from the Informal Group on Amendments to UN R55.01.

Text as approved by the GRRF and prepared by the UN R55 informal group to update this regulation with respect to:
a) Requirements on remote indication,
b) Availability of information on coupling fixing points for A50X couplings,
c) On lateral strength of drawbars, and
d) a new class definition for fully automatic drawbar couplings.

Proposal to ensure that coupling balls do not block rear lighting and/or registration plates. In line with the EU General Safety Rule, Annex IV specification for application of UN R55, couplings that might block lighting or plates must be removable, repositionable, and unlockable in order to make it easier for users to remove them or reposition them when not in use (e.g., towing a trailer.) Coupling balls that are so designed as to be unable to block lighting or plates may still incorporate locks and/or require tools to remove or reposition.

Reworked and restructured version of document TFAC-05-10.

Reworked version of document TFAC-05-10.