I looked but don't see anything that addresses this, but I'm obviously missing it.
What is the standard (if any) for the wavelength or color of for the red, yellow, green on traffic lights? Is there a range of acceptable reds, or is a specification that must be met?
Thanks
There must be, because it took a while in the start of the LED era to get an acceptable green light. Guidelines assumed the light source would be yellowish incandescent, so red and yellow came along before a LED green. I know the walk signal must be "astronaut white," which worked great with early white LEDs.
Those are not wavelength standards, those are color standards. There are a few, and there was some discussion here, in your previous thread:
https://www.aaroads.com/forum/index.php?topic=21071.0
I still suggest as I did previously that you do read Wiki about colors and how they are defined.
Quote from: ErmineNotyours on October 06, 2018, 11:00:49 PM
There must be, because it took a while in the start of the LED era to get an acceptable green light. Guidelines assumed the light source would be yellowish incandescent, so red and yellow came along before a LED green. I know the walk signal must be "astronaut white," which worked great with early white LEDs.
I know that early green LEDs were a lime green, which was the wrong shade of green for traffic signals.
Also, "Lunar White" was never standardized prior to the LED era for walk signals. While it was in use by some cities by placing a light blue filter over the incandescent light source; this was not universally applied. Since early white LEDs were that shade, it became the standard color for walk signals.
No clue, anyone notice how older GE red LEDs appear orange, not too friendly for the colorblind folk