Proposal to amend UN R53:

• Simplify para. 2 by deleting vehicle type definition and consolidating definitions from UN Regulation No. 48,
• Consolidate para. 5 general specifications by reorganising lamp positioning requirements into para. 5.5. and 5.6., restructuring geometric visibility provisions, and clarifying electrical connections,
• Consolidate para. 6 individual specifications by standardising positioning formats into minimum/maximum height tables and reformatting geometric visibility angles into upwards/downwards/outwards/inwards notation,
• Delete para. 5.20. as its content moves to para. 5.6.,
• Delete Annex 3 as its content references UN Regulation No. 48,
• Simplify transitional provisions by deleting para. 11.1. through 11.11. and para. 11.12. and replacing with new para. 11.1. and 11.2. containing simplified provisions applicable to the 05 series of amendments with dates to be determined (1 September 20xx),
• Add Annexes 10 and 11 containing summary tables of lamp positioning and geometric visibility angles.

At the 77th SLR meeting (Brussels, April 2026), participants reviewed and improved baseline documents for UN Regulations 48, 53, 74, and 86, reflected in SLR-77-08/Rev.1, SLR-77-09, SLR-77-10, and SLR-77-07 respectively. SLR approved a revised proposal to correct errors in Reg. 150-01 (SLR-77-06/Rev.1, superseding GRE-94-02) and a compromise text prohibiting additional lamps unless complying with national requirements. SLR agreed to postpone official document submission to GRE-96 (April 2027) and will submit 11 informal documents to GRE-94, including status report, four baseline documents, four highlights slides, a proposal on technological neutrality, and the revised correction proposal. Discussions on apparent surface, direction indicator visibility, and direction indicator lamp height will resume at SLR-78 (June 2026).

This document discusses single lamp distance requirements in context of Apparent Surface simplification pursuant to discussions with Contracting Parties. The current 75mm separation value was not based on studies but on considerations. A 1999 IENGF Milano study concluded that larger distances are acceptable for symmetric constellations, with AFS lighting units spaced up to 200mm. A minimum 600mm separation is mandatory if right and left mounted functional unit identification is required. No evidence of increased accident risk, misidentification of signal, reduced conspicuity, or regulatory enforcement issues from current single lamp separation distances exists. The simplified CAD-based Apparent Surface concept will be based on light emitting surface with clear outer lens disregarded. GTB suspended work on this topic due to insufficient consensus and difficult stakeholder alignment, pending additional information on single lamp separation distance.

The 78th session of the GRE Informal Working Group on Simplification of UN Lighting and Light-Signalling Regulations was held in Brussels, 10-12 June 2026. SLR decided not to include a new Part 7 on Colour-fastness in Annex 6 to Regulation 150-01 and will submit a consolidated correction proposal to GRE-95. Discussion on apparent surface definitions and single lamp distance requirements will resume at SLR-79, with wider consideration of related topics including glare and direction indicator visibility. Baseline documents for Regulations 48, 53, 74, and 86 were reviewed and updated versions will be prepared for the next session. The next SLR meeting will be held in Tokyo on 7-11 September 2026.

The agenda includes adoption of previous session reports, correction of errors in Regulation 150-01, improvement of direction indicator visibility, rearrangement of lamp provisions in Regulation 48, consistency checks for geometric visibility angles, baseline documents for Regulations 48, 53, 74, and 86, review of transitional provisions, discussion of apparent surface definitions, and submission preparation for GRE-95.

Proposal to:

• Modify para. 1 of Scope to include vehicles of categories S, agricultural and forestry NRMM, and category T vehicles,
• Amend para. 2 to restructure definitions for vehicle type, lamps, dimensions, and retro-reflectors,
• Delete redundant definitions,
• Add general provisions for lamp position and geometric visibility,
• Modify para. 3 regarding type-approval documentation,
• Amend para. 4 to reference Schedule 4 of the 1958 Agreement (E/ECE/TRANS/505/Rev.3),
• Reorganise para. 5 to establish general specifications and consolidated provisions for lighting connections, tell-tales, concealable lamps, lamps of variable position, and provisions regarding light confusion,
• Amend para. 6 to revise individual specifications for all lamp functions with revised formatting, measurements, and geometric visibility angles, including new requirements for driving-beam and passing-beam headlamps, front fog lamps, reversing lamps, direction-indicator lamps with arrangements A through E, hazard warning signals, stop lamps, front and rear position lamps, rear fog lamps, parking lamps, end-outline marker lamps, work lamps, retro-reflectors (front and rear, triangular and non-triangular), side-marker lamps, daytime running lamps, cornering lamps, conspicuity markings, rear registration plate illuminating lamps, manoeuvring lamps, SMV rear marking plates, exterior courtesy lamps, and signalling panels or signalling foils,
• Modify paras. 7 to 10 regarding modification, extension, conformity, penalties, and discontinuation of production,
• Amend para. 11 regarding technical services and type-approval authorities,
• Restructure para. 12 with transitional provisions for the 04 series of amendments with mandatory application dates of 1 September 20xx,
• Revise Annex 1 communication form to reference the 04 series of amendments and update lamp designations,
• Revise Annex 2 to reflect 04 series of amendments in approval mark examples,
• Replace Annex 3 with new Annex 3 containing visibility zones for red and white light (para. 5.11.4),
• Replace Annex 4 (Direction-indicator lamps geometry) with new Annex 4 containing informative summary tables for lighting and light-signalling installation rules for vehicles of categories T, R, and S,
• Replace Annex 5 (replacing former Annex 6) with updated specifications for signalling panels and signalling foils, applicable from 1 September 20xx.

Proposal to amend UN R74:

• Simplify definitions by referring to UN Regulation No. 48,
• Replace vehicle type references with vehicles of category L₁,
• Use hyphens in “type-approved” and “direction-indicator lamp”,
• Add provisions for electric vehicle inclusion,
• Consolidate general and individual lamp specifications,
• Reorganize geometric visibility requirements into paragraphs 5.5 and 5.6,
• Add para. 5.22 regarding lamp operation requirements,
• Create summary tables in Annexes 6 and 7 for lamp positioning and geometric visibility angles,
• Revise approval marks in Annex 2,
• Reserve Annex 3,
• Establish transitional provisions for the 04 series with dates to be determined (1 September [20xx]).

Simplification work on UN Regulation No. 86 addresses five pending points: the number of additional direction-indicator lamps allowed, geometric visibility of category 6 direction-indicator lamps, height for slow-moving vehicles marking plates set as low as possible above the ground but not less than 250 mm at the lower edge, position for slow-moving vehicles marking plates with regard to the vehicle median longitudinal plane, and speed for automatic activation of manoeuvring lamps proposed at 15 km/h as a compromise.

SLR will deliver Stage 2/Step 2 to GRE-96 by end of January 2027 for submission to WP.29 in November 2027. SLR’s mandate ends December 2027. A new informal working group on Supporting technical experts on Lighting Regulation (SteLR) will be established, chaired by EC and vice-chaired by Germany, to address remaining open points from SLR and TF-GP. Main topics include visibility of signalling functions, glare prevention, apparent surface, energy saving, replaceability and sustainability, and V2X communication.