system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: why aren't traffic lights made with one light that changes color instead of three. Wouldn't they be easier to manufacture and install?
gpt
Several reasons. Technology has only recently evolved to where this would actually work. Prior to LEDs, all bulbs were white with colored filters in front of them and having the filters change mechanically would be a huge failure point. Our eyesight notices movement much quicker than color changes and the change in location of the light acts like motion. And what about all of our color blind friends? The position of the light helps them to know which one is on.