The agenda includes corrections to UN R150-01, baseline documents for UN R53, R74, R86, and R48, simplification of paragraphs 6.×.4 and 6.×.5, transitional provisions, harmonisation of requirements, apparent surface considerations, and direction indicator visibility improvements. The next meetings are scheduled for June and December 2026, with a potential September 2026 session in Tokyo.

This document addresses rear direction-indicator lamps mounted at low positions on vehicles. Republic of Korea reports increased public petitions and media articles regarding visibility and recognition concerns, particularly in congested traffic and for vehicles with higher driver seating positions like SUVs. UN Regulation No. 48 specifies direction-indicator lamp height requirements: not less than 350 mm and not more than 1,500 mm, or up to 2,100 mm under certain structural conditions. The presentation seeks feedback on similar issues from other countries and manufacturers.

A literature review on direction indicator visibility presents research on vehicle lighting design, visibility, and signalling. Sources include studies on overlapping and interlocking of lights, and dynamic evaluation of automobile rear lighting configurations.

The document analyzes separating direction indicators and stop lamps. It examines how drivers recognize lighting functions through visual perception and notes that irregular lamp shapes increase reaction time. The document states that “apparent surface”, currently defined only through manufacturer drawings, lacks perceptual grounding because it ignores luminance distribution and edge contrast. It recommends minimum lamp sizes and distances based on visual acuity, minimum luminance requirements, and a 3:1 luminance contrast between functions when spatially merged in one lamp.

OICA presents research findings on direction indicator perceptibility when stop lamps activate simultaneously. Key findings indicate that spatial separation between functions, increased direction indicator intensity, and relative signal dominance improve perception. Research shows stop lamp luminance can reduce direction indicator recognition, particularly in near-field viewing. OICA concludes that minimum size requirements proposed in the German proposal exceed available evidence and may create unintended consequences without demonstrated safety benefits.

Proposal to introduce a clarification of grouped markings and labels. Further details can be found in informal document GRE-94-07.

Proposal to clarify and modernize lamp installation and component requirements in UN R48 and UN R148 to address the growing variety of vehicle and lamp designs, particularly band/strip lamps extending across the full width of the vehicle. Key changes include: removing the “band/strip” terminology and expanding the definition of a pair of lamps to cover full-width designs; removing the three-device maximum for Y-lamps to ensure technology neutrality; adding a new paragraph §5.5.5 defining a pair as a two-lamp system; relocating light source requirements from UN R48 to UN R148 §4.7.3 to ensure at least one light source per side; removing the 0.8-metre minimum length requirement; and clarifying that definitions in §2.4.10 apply only to the relevant vehicle categories. Minor amendments to UN R148 include updated provisions for light source positioning, clarification of §4.8.1.3, and new sampling provisions in §4.8.11 for testing band/strip lamps. Further details can be found in informal document GRE-94-03.

Proposal to introduce selective yellow as an permitted alternative to white for front position lamps and daytime running lamps in UN R48 and UN R148. Studies confirm that selective yellow performs equally to white for oncoming vehicle recognition and speed estimation. Unlike historical filament lamp applications where a yellow filter reduced luminous intensity, modern LEDs achieve the same intensity levels without reduction. Specific amendments include: updating §5.15 to reflect selective yellow options and removing a duplicated front fog lamp requirement; amending §§6.9.7 and 6.19.7 to deactivate selective yellow position and daytime running lamps on the relevant side during direction indicator activation; and aligning UN R148 (01 series) by amending §§5.1.7, 5.4.7 and Annex 1 accordingly. The colour boundaries for selective yellow are already defined in §2.11.1.2 and require no amendment. Further details can be found in informal document GRE-94-05.

Proposal to correct an editorial error regarding the markings for light source control gear, to clarify the calculation method (i.e., rounding down to three digits) for the acceptance criteria in cases where tolerance limits are calculated, and to delete provisions concerning the Unique Identifier pursuant to the decision to change its application from “by default” to “if specified in the regulation”.