How do they change the light bulbs in traffic signals?

I mean, obviously they don’t stick a ladder up in the middle of traffic, so how do they do it? Also, how do they figure out that they are burned out in the first place? Do they wait for accidents to start happening, or do they have some kind of sensor?

In my neighborhood DOT sends a cherry-picker and a guy with a lightbulb. I have also called DOT to tell them the light on my corner wasn’t working. I wasn’t the only one who called, apparently. Someone in a cherry-picker was there within 15 minutes.

Bucket truck. It’s not a fun job. If it has happened in your city, bulbs are giving way to L.E.D.s Look closely at the red lights. They last lots longer. Use less power too. Important in California.