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.

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.

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.

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).

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]).

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.

The 76th SLR session (4–6 February 2026) reviewed and improved baseline documents for Regulations 48, 53, 74, and 86 for Stage 2/Step 2 submission to GRE-94 as informal documents. SLR approved simplification of paragraphs 6.×.4. and 6.×.5. in Reg. 48 and agreed on technological neutrality amendments to Reg. 48 and a compromise text for Reg. 149. SLR approved a compromise text on “Prohibited if not allowed” for final check at SLR-77. Discussions on apparent surface and direction indicator visibility will resume at SLR-77. Transitional Provisions for the 10 series will be reviewed at SLR-77. The 77th, 78th, and 79th meetings are scheduled for April, June, and September 2026.

The GRE Informal Working Group on Simplification of UN Lighting and Light-Signalling Regulations held its 73rd session in Brussels on 9-11 July 2025. SLR approved reports from the 70th and 71st sessions. The Homework Team R-150 will prepare an updated version of SLR-73-09 including a decision tree and justification for submission to GRE-93 or GRE-94. SLR experts will study the GTB draft proposal in SLR-73-04 (superseded by SLR-73-04/Rev.1) to simplify paragraphs 6.×.4. and 6.×.5. in Reg. 48. SLR-73-07/Rev.1 reflects the latest baseline document for Reg. 48 with agreed modifications. IMMA introduced baseline documents for Reg. 53 and Reg. 74 reflecting simplified definitions. CEMA will prepare a baseline document for Reg. 86. GTB will prepare an updated proposal for a CAD-based method to determine apparent surface for SLR-74. A special SLR session on apparent surface may be held on 10 September 2025 if equipment is available. Discussion continues on harmonisation of requirements, improving direction indicator visibility, and technological neutrality for light sources. The 74th SLR meeting is scheduled for 10-12 September 2025 in Brussels.

The 74th SLR meeting (Brussels, 10–12 September 2025) reviewed baseline documents for Regulations 48, 53, 74, and 86, with participants improving draft texts on simplified paragraph structures and definitions. Key topics included correction of errors in Regulation 150 (formal proposal for GRE-94 April 2026), apparent surface simplification with support for Alternative A and luminance method consideration, improved visibility of daytime running lights (OICA drafting proposal for December session), and harmonisation of requirements regarding prohibited if not allowed (seeking GRE feedback). Technological neutrality for light sources was deferred to informal discussions. The 75th meeting is scheduled for 10–12 December 2025 in Brussels.

The GRE Informal Working Group on Simplification of UN Lighting and Light-Signalling Regulations held its 75th session in Brussels, 10–12 December 2025. SLR reviewed and improved revised baseline documents for Regulations 48, 53, 74, and 86, reflected in SLR-75-10/Rev.1, SLR-75-16/Rev.1, SLR-75-17, and SLR-75-21 respectively. SLR endorsed corrections to Regulation 150-01 in SLR-75-02/Rev.1 and simplified paragraphs 6.×.4. and 6.×.5. in Regulation 48 per SLR-75-05/Rev.1 (superseded by SLR-75-05/Rev.2), with continued discussion at SLR-76. SLR tasked GTB to complete work on apparent surface definition and CAD method. SLR agreed the 76th meeting will be held 4–6 February 2026 in Brussels.

Proposal for supplement to the 01 series of amendments to UN Regulation No. 150, amends SLR-78-07/Rev.1. Proposal to reduce the number of samples required for approval from ten to eight, delete references to colour-fastness testing and weathering resistance testing from paragraph 3.5.3.1., amend paragraphs 5.1.2., 5.1.3.1., and 5.1.7. to reflect the reduced sample requirement and revised test protocol, replace “light emitting surface” with “illuminating surface” in Annex 5, amend Annex 7 paragraph 1.1. to replace “apparent” with “noticeable” when describing surface changes, delete columns i and j and associated test rows from Tables 4 and 5, and delete Annex 11 Guidelines for installation of rear marking plates on slow-moving vehicles.

Proposal to amend approval marking and Unique Identifier requirements:

• Clarify conditional requirements for approval markings and Unique Identifier usage in the Introduction,
• Delete paragraph 3.3.3. on Unique Identifier provisions,
• Renumber paragraphs 3.3.4. through 3.3.6. as 3.3.3. through 3.3.5.,
• Amend paragraphs 3.3.1.1., 3.3.1.3., 3.3.5. and sub-paragraphs, and 3.3.6. and sub-paragraphs to remove references to Unique Identifier and reorganize marking requirements,
• Add new paragraph 3.3.2.5. requiring a downward arrow for devices with reduced light distribution,
• Amend paragraph 5.1. to expand class specifications from IA and IB to IA, IB, IIIA, IIIB and IVA,
• Restructure paragraph 5.1.3.1. testing procedures with new sub-paragraph 5.1.3.1.1. for Classes IA, IB, IIIA and IIIB and new paragraph 5.1.3.1.2. for Class IVA specifying distinct sample groupings,
• Amend paragraph 5.1.7. to create separate Tables 4 and 5 for chronological test orders for Classes IA, IB, IIIA, IIIB and Class IVA respectively,
• Amend paragraphs 5.2.3.3., 5.2.5.1.1., 5.2.5.2.1., 5.2.6.3., 5.2.6.4., and 5.3.4.2.,
• Insert new Table 8 with chromaticity coordinates and luminance factor requirements for Classes 1, 2, 3 and 4,
• Renumber existing Tables 8, 9 and 10 as Tables 9, 10 and 11,
• Amend paragraph 5.3.5.2.2.,
• Delete paragraph 5.2.5.2.1.,
• Amend Annex 1 Item 5. and para. 10 to remove Unique Identifier references,
• Amend Annex 5 paragraph 8.1.4.,
• Amend Annex 6 Part 2 paragraphs 1.3.2. and 2.1.3. and Part 4 paragraph 4.2.,
• Amend Figure A10-1 in Annex 10 to clarify marking arrangement requirements and remove diametrically opposite placement requirement for class symbols.

This document is a baseline for UN Regulation 48 (Stage 2/Step 2) concerning vehicle lighting and light-signalling devices. It incorporates all amendments from multiple series and includes provisions for adaptive front-lighting systems (AFS), driver assistance projections, reversing projections, direction-indicator projections, and automated driving system (ADS) features. The regulation establishes requirements for the design, installation, and operation of lighting devices on vehicles of categories M, N, and O, with comprehensive specifications for individual lamp types, geometric visibility angles, electrical connections, and tell-tale requirements. It includes transitional provisions allowing approvals under preceding series while establishing phased implementation timelines for new requirements.

The 79th SLR Informal Working Group Meeting will be held 7–11 September 2026 at AP Ichigaya, 8th Floor, AP Ichigaya, Ichigaya Osato Building, 1–10 Gobancho, Chiyoda-ku, Tokyo 102–0076, Japan. A reception is scheduled for 9 September 2026 at 18:00–20:00. The meeting includes sessions on Task Force on Glare Prevention and Task Force on Lamps Under Parked Conditions and Task Force on Autonomous Vehicle Signalling Requirements, though it has not yet been decided whether the latter two task forces will be held during the Tokyo meetings. Participants should complete the registration form.

Proposal to amend para. 3.5.3.1. to delete reference to colour verification of retro-reflecting optical units, amend para. 5.1.2. to reduce required samples from ten to eight, amend para. 5.1.3.1. to reduce samples from ten to eight and divide remaining six samples into three groups of two, insert para. 5.1.3.1.1. specifying Classes IA, IB, IIIA and IIIB, amend para. 5.1.7. to delete sample columns i and j from Tables 4 and 5 and delete the weathering resistance test row, and amend reference to Part 4 of Annex 6 to Part 5 of Annex 6 in both tables.

Proposal to amend UN R86 on approval markings and testing requirements:

• Delete provisions regarding the Unique Identifier and conditional use of conventional type approval markings from the Introduction
• Amend para. 3.3.1.1. to delete reference to the Unique Identifier
• Amend para. 3.3.1.3. regarding approval marking proportions
• Add new para. 3.3.2.5. requiring a vertical downward arrow for devices with reduced light distribution
• Delete para. 3.3.3. on Unique Identifier entirely
• Renumber para. 3.3.4. as 3.3.3.
• Renumber para. 3.3.5. as 3.3.4. and amend to delete reference to Unique Identifier
• Renumber para. 3.3.6. as 3.3.5. and amend to delete reference to Unique Identifier
• Amend para. 5.1. to include Classes IIIA, IIIB and IVA
• Amend para. 5.1.3.1. regarding heat resistance testing and divide samples into groups for testing Class IA, Class IB, Class IIIA and Class IIIB
• Add new para. 5.1.3.1.2. for Class IVA testing
• Amend para. 5.1.7. to create separate Tables 4 and 5 for chronological order of tests for Classes IA, IB, IIIA, IIIB and Class IVA respectively
• Amend para. 5.2.3.3. to reference Part 1 of Annex 6 and paragraphs 5.2.5. and 5.2.6.
• Amend para. 5.2.5.1.1. regarding coefficient of retro-reflection measurement
• Delete para. 5.2.5.2.1. entirely
• Amend para. 5.2.6.3. to include colour requirements and insert Table 8
• Amend para. 5.2.6.4. regarding luminance factor
• Renumber Tables 8, 9 and 10 as Tables 9, 10 and 11
• Amend para. 5.3.5.2.2. to reference Table 11
• Amend Annex 1 Item 5. and delete reference to Unique Identifier in Item 10
• Amend Annex 5 para. 8.1.4. to correct cross-reference to para. 5.3.4.2.1.
• Amend Annex 6 Part 2 para. 1.3.2. to reference para. 5.2.5.1.
• Amend Annex 6 Part 2 para. 2.1.3. to correct paragraph references
• Amend Annex 6 Part 4 para. 4.2. to reference Table 6 only
• Insert new Part 7 in Annex 6 on colour-fastness for Classes IA, IB, IIIA, IIIB and IVA
• Amend Figure A10-I to clarify marking arrangement rules and delete the diametrically opposite requirement

The agenda addresses correction of errors and omissions in UN Regulation 150-01, including a consolidated proposal merging GRE-92-18, GRE-94-02/Rev.1, GRE-94-11, and GRE-94-24, and a decision on addition of Part 7 on Colour-fastness to Annex 6. Baseline documents for UN Regulations Nos. 48, 53, 74, and 86 will be reviewed, along with transitional provisions. The group will consider visibility of direction indicators and Korean concerns regarding rear direction indicator lamp height. The 79th meeting is scheduled for Tokyo in September 2026.

This baseline draft for UN R48 (10 series of amendments) establishes uniform provisions for vehicle lighting and light-signalling device installation. The document reflects all modifications agreed at GRE-94 and incorporates an updated proposal from IEC regarding technological neutrality for LS devices. Key additions include provisions for work lamps to be included after formal WP.29 adoption in June 2026, updated tables for positioning and geometric visibility angles (Annexes 18–19), and revised terminology replacing “dipped-beam/main-beam” with “passing-beam/driving-beam” throughout. Open points address apparent surface visibility against stop lamps and consistency with IWVTA transitional provisions, with transitional provisions for the 10 series specifying acceptance dates and phase-in periods to be finalized.