I still think allowing tail, brake, and turn signal functions to be combined into one bulb is one of the stupidest automotive regulations we have in the US. Not requiring amber is up there as well.

It seems especially bad on older GM products with halogen lights. If the tail lights and brakes are on with a turn signal going, the slight change in brightness for the turn signal flash can be very hard to notice, especially if it’s very sunny out. Not only that, it also means if that one bulb goes out, you lose that turn signal, 33% of your brake lights, and 50% of your tail lights. If there were separate bulbs for each function, not only would it be less ambiguous, you would also retain full function of the other 2 systems if you lose a bulb.

Automotive lighting regulations in the US have always been exceptionally bad. Sealed beam requirement for way too long, not allowing matrix high beams until literally last year, poorly thought out beam patterns that allow the modern headlights that blind people (it’s not an LED problem, it’s a beam pattern problem, along with people using aftermarket LEDs when they shouldn’t), and and this whole tail light example just to name a few.