Who turns on the streetlights when it gets dark?

Question

are there timers? or is there a giant light switch that turns all of them on at once? i saw one go on earlier and it got me wondering.

Answer 1

They have light sensors built into each lamp.

Answer 2

will i wonder the same thing, i think the city has a big light switch some where in the city and when it gets dark a city worker turns it on and when it gets light out a city worker turns it off., or it might be done by a computer

Answer 3

Sometimes it's on a timer but most often the lights are controlled by an LDR - a light dependent resistor. When it gets dark outside (which is not always at night due to storms/clouds etc) the feedback to the lights is to turn on/off automatically.