how do streetlights work ive been told a few different answers?

Question

how do streetlights work ive been told there on timers ive been told there are pressure plates under the road i want a real factual answer please

Answer 1

Did you mean traffic signals? You said streetlights, but when you started mentioning pressure plates, I surmised that you did not mean the lights that come on at night.

Assuming you do mean traffic signals... It depends on the intersection and equipment installed. Yes, many systems do have sensors, some under the road, that sense the presence of a vehicle, not so much "pressure plates" but "metal detectors". This is also very common to engage turn arrows. If no cars are waiting to turn left, the left turn arrow will often not come on if the sensors are present. You are also right about the timers, the lights are also timed and many use a combination of timers and sensors.

Hopefully that was more factual than the fairy answers you got.

Answer 2

Street lights or traffic signals?

Streetlight work on light sensor, at night or a very cloudy day they turn on or off depending on the amount of light they detect on the sky.

Traffic signals work on "electronic timers" some are more computerized than others. No pressure plates needed.

Answer 3

If there is no one there to see the light, is it really on?

There are different kinds of systems where electric wires go under the sidewalks, and there is some kind of timer switch so the lights come on at night, and are off during the day.

Traffic Lights use several systems, in which it is not in the best interests of National Security to be publicizing how this system works, since all sorts of mischef makers are out there interested in spoofing the system for nefarious purposes.

Different cities & locations different systems, such as not use left turn arrow if there is no traffic there needing it.

Answer 4

Streetlights are turned on at dusk and off at dawn by an ambient light sensor located on top of the lamp housing.

Answer 5

Are you asking about street lights, or traffic signals? Only older traffic signals use the pressure plate method of determining traffic. Street lights, which give general lighting, come on when it gets dark because they have a light sensitive eye watching the north sky which turns them on at dusk and off at dawn.

Answer 6

THERE ARE TWO WAYS THEY COME ON AND OFF, PENDING ON LOCATION OF THE LIGHTS IE MID AFTERNOON SHADED AREAS SO ON SO FORTH.

ONE BEING A TIMER, THAT @ A CERTAIN TIME THEY COME ON OR OFF.

SECOND BEING A VISABILITY SENSOR, MEANING WHEN VISABILITY GETS LOW THE LIGHTS COME ON, WHEN VISABILITY IS GOOD THEY TURN OFF

Answer 7

Light sensors.
As daylight goes away, the sensors tell the street lights to come on.

Answer 8

For every street light there is a invisible inslaved fairy that runs the street lights with magic. The lights themselves are trapped demonic spirits.

Answer 9

For every street light there is a invisible inslaved fairy that runs the street lights with magic. The lights themselves are trapped demonic spirits.

Answer 10

The ones where I live have photo-cells on them and come on at dusk.