George Herold formulerede spørgsmålet:
2: In incandescent traffic signals, the bulbs for yellow last longer
than
for red and green. So even after being switched on and off about a
million times, on-time is still a significant factor in life
expectancy.

However, traffic signal bulbs have a more vibration-resistant
filament
than standard incandescents.


I've been told traffic signals have resistors across the relays (or the
semiconductor equivalent), so the bulbs are never turned completely
off, eliminating the turn-on surge.

But it may be just rumours...

(Yes, I know its an old'ish message)


--
Husk kørelys bagpå, hvis din bilfabrikant har taget den idiotiske
beslutning at undlade det.