Comment by kube-system
6 hours ago
> It's not hard to imagine the partially legitimate reason that on occasion, someone will drive with the trunk open
No, it's a much more serious and likely reason -- people stopping on a highway at night, getting out, and opening their trunk for some reason (like a spare tire, fluids, etc)?-- then their lights (and the reflectors in the lamp housings) are pointed at the sky.
Or, movable bodywork is more prone to be misaligned during normal operation.
Headlights get out of alignment sometimes. I posit that likelihood goes up if the lights are themselves mounted on a hood/door/whatever that can also go out of alignment.
Yeah that is important for headlamps -- but for signal and marker lamps, the point is visibility.
My dad, in the 1960s, put reflective tape on the rear bumpers.
He was on the right track. I put truck trailer tape on the inside lid of the trunk, not so visible when in normal operation. All of our motorcycles, OTOH, have strips of trailer tape right down the saddlebags because safety over aesthetics.
Some automakers have chosen to meet the standard while keeping their lights on movable panels by placing additional lights/reflectors in the bumper to meet requirements.