![Why do traffic lights have three separate light bulbs instead of having one? - User Experience Stack Exchange Why do traffic lights have three separate light bulbs instead of having one? - User Experience Stack Exchange](https://i.stack.imgur.com/k7cyJ.png)
Why do traffic lights have three separate light bulbs instead of having one? - User Experience Stack Exchange
![Jonathan (he/him) on Twitter: "@ellenfromnowon it's a green circle. When the bike lane light goes red, that light goes green the forward arrow filter light goes out." / Twitter Jonathan (he/him) on Twitter: "@ellenfromnowon it's a green circle. When the bike lane light goes red, that light goes green the forward arrow filter light goes out." / Twitter](https://pbs.twimg.com/media/DyG_RzWX4AIffK1.jpg)
Jonathan (he/him) on Twitter: "@ellenfromnowon it's a green circle. When the bike lane light goes red, that light goes green the forward arrow filter light goes out." / Twitter
How long will you sit behind someone at a recently green traffic light before honking at them? - Quora
![UK Traffic Lights at Dawn Against Grey Sky with LED Streetlights in Background Stock Image - Image of streetlight, left: 182119321 UK Traffic Lights at Dawn Against Grey Sky with LED Streetlights in Background Stock Image - Image of streetlight, left: 182119321](https://thumbs.dreamstime.com/z/uk-traffic-lights-dawn-against-grey-sky-led-streetlights-background-stop-light-left-turn-straight-ahead-arrows-lit-182119321.jpg)