I don’t understand how they work, what they’re hooked up to and how they know when to turn from green, to yellow, to red. Are they timed? Is there a sensor, perhaps a small man hiding in the pole controlling it?
In: 7
Theres multiple different ways they function. They tend to either work on a pressure sensor (the lines in the ground in front of the light), on a timer, or on a motion sensor. Emergency vehicles have a device that can override them and force them to change. Most major cities also have a traffic control center that can change the function of each light throughout the day depending on traffic conditions.
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