Re: Question for OPB
Author: mook
Date: 10-20-2010 - 17:43
Thanks for the great explanation! You're right; highway signals don't have nearly the same requirements -- but then everybody ignores them when they feel like it anyway so why be too picky?
There are Federal color requirements for traffic signals, and the early LEDs (Calif has used LEDs at least in red lights for 20 years) sometimes didn't follow them well enough. Things are fairly well standardized now, and enforcement has never of course been of the "go to Leavenworth" variety.
The heat issue sounds silly but isn't. LED highway signals aren't loved by snow-area maintenance crews because they *do* get packed with snow sometimes which the old light bulbs would eventually melt away, at least in the red light which is on the most (yes it's true...). Hanging over traffic in a busy intersection cleaning out the signal head isn't much fun. I suspect that highway depts with Real Winters might be very interested in LED heads with built-in heaters.
;-)