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.