Are road signals controlled by logic and timers or is it controlled.?

Question

Are road signals controlled by logic and timers or is it controlled by someone sitting somewhere? Do the signal intervals change during rush hour or is there is any built in logic that senses the traffic and trigger the signals? What are the variables on which traffic signal work and do the logic and interval change during different times of the day or change depending on the intensity of traffic?

Answer 1

The default is to have the traffic light controlled by timers.  Different time of day causes different traffic pattern.  If you think about it, small towns have no choice but to automate everything.  And big cities have too many signal light but to let timers (and computers) control everything.

But recently many big cities are putting in part human logic.  If at some head quarters, they sense (or see on their close circuit cameras) that there are congestion, the person sitting at the head quarters can make inputs to divert traffic else where (or to make the traffic flow better in one direction or another.

I live in NYC and they are often showing what the dept of traffic are doing to make traffic flow better.  And this is exactly what they do (mostly automatic timer / computer but with human override with extra congestion).

Good luck.

Answer 2

There are some road signals that are controlled on a timer, usually allowing more time for the busier street at the intersection to go. Then, there are some road signals that are controlled by a human. But they are mostly at special events, such as concerts or something. And then there are the traffic lights that have sensors on the streets. So if a car is waiting it recieves a signal from the sensor and switches to allow that car to go. We have a lot of those last ones down in South Florida.

Answer 3

There are a variety of controls for the street lights.  A lot of them use the roll over controls where there is a coil of wire buried beneath the asphalt that will send a signal to the controller and cause the street light to start a cycle.

In the downtown area some are controlled from a central computer that will synchronize the lights so that traffic flows at a smooth rate.  Especially at rush hour, this lets people get out of the downtown area faster and less congestion.

good luck.

Answer 4

They are controlled by computers and are set to vary the timing of the lights  according to the time of day and the traffic load.   Sometimes, the lights around concerts, etc. are controlled manually by police officers that have a controller and are in visual contact with the light. This is so that traffic can flow at the optimum rate around the area.