The 37th session reviewed a consolidated working document on automotive life cycle assessment integrating comments from Contracting Parties, stakeholders, and the European Commission. Key unresolved issues include electricity modelling, chain of custody, primary data share, logistics, battery replacement, and vehicle lifetime assumptions. The leading team will update the overview table and identify priority issues for discussion. The next session is scheduled for 9 April 2026, with an internal milestone of 19 June 2026 to resolve outstanding issues.
GTB proposes simplifying UN R48 by developing a single CAD-based method to determine apparent surface at early design stages. The proposal deletes the “light-emitting surface” definition and establishes “apparent surface” as the orthogonal projection of visible light-emitting surfaces in a specified observation direction. Amendments include revised definitions for lens, textured outer lens, illuminating surface, and apparent surface, with modified requirements for single lamps with multiple distinct parts. Distance requirements between adjacent parts are adjusted to 75mm or 200mm depending on lamp type.
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.
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.
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.