Does anyone know how actual traffic lights are controlled? Is it a central control centre where there are cameras at junctions being monitored by humans or stand-alone systems where each junction is controlled independently by a computer in one of the light boxes? Or is it completely different depending where you are in the world? I live in Exeter, Devon, UK, and there seems to be a huge amount of traffic lights everywhere, I believe the second most traffic lights per mile of road. Even round-abouts have traffic lights on them, which I think there shouldn't be as round-abouts are self regulating.
Anyway, back on topic, I remember doing the typical traffic light controller assignment in school, and the smart a** I was, I added a time of day reference so all lights flash amber after 10.30pm. I got marked down for not following the assignment!