Not in London. Nearly every day I see a new failed one. There is usually redundancy tho

That seems like the right approach. The traffic light has a backup bulb and alerts when one burns out. I mean, cars can tell when a bulb is out, right? Why shouldn't traffic lights.

Actually it's even simpler than that, just have a minimum of 2 lights per direction of travel.

So if one fails, a bulb burns out, one gets destroyed in a storm, or anything else happens, there will be at least one full backup.

Having automated outage reporting still makes sense though. It keeps you from having a guy that's paid to check every light in the city manually. And since your lights are on a city-wide network (they are, right?), then adding outage reporting should be a feasible thing.