How are stop lights triggered ?

Question

You know..late at night..when there arent a lot of people out....how and where are the stop lights triggered

Answer 1

Most definantly the streets sit on metal sensors that sense whether cars are present. Then the signal is sent to a a green/ blue box ( most of the time) and the box regulates the signals the box can also be used to controll traffic manually that is how police can control the lights without being in the street themselves. Also illegal remote controlls can control the box to make it switch the light.

Answer 2

We use an antiquated system that waste time and gas for the most part. They are triggered by ways others have answered. The problem is they will stop 50 cars to let one car go through. Great idea if you are collecting gas tax and you don't give a hoot about your country going broke. There are systems that can eliminate "unused green" and that 50 car stop for one to go. Don't look for them in this country though unless the dumb voters wise up. (unused green is sitting at a stop light with no cross traffic just burning up gas)

Answer 3

Some are simply on a timer, others are triggered by weight sensors in the street. When a car is on them, the light will change.

Answer 4

Some are on a timed cycle, and others use sensors imbedded in the roadway. It's not a weight sensor but a proximity sensor that responds to the metal content in the vehicle. Some of the newest systems use cameras that monitor traffic well before it gets to the intersection.

Answer 5

that depends. in my old city, there was some on timers and then there was some on sensers that had squares in your lane where you would stop and that would trigger them to change.The squares are just a big square about the size of the car.In an neighboring town there are ALOT of big hills, so they use timers so ppl don't get stuck half up a hill on ice when it's snowing or have to worry about semi's driving sticks and how they roll back when they start to go.Ive even seen on the construction zones the laser sense.It's nice having to stop and no one coming from the other side you can juts go on through!

Answer 6

Some stop lights are on timers, others have sensors under the road to sense when a vehicle is on them and some have overhead sensors pointing at the road.
Dave

Answer 7

I think the ones here have a gnome that hates me inside of it because late at night it takes FOREVER for the light to turn green even if I am the ONLY car on the streets...

Answer 8

position a magnet from a speaker field or refigerator (reliable magnet) on the bottom of your body. Google "bike red elementary hack". that is going to instruct you an similar. There are even some places you are able to yet a lined magnet to compare your bike. i have were given a magnet from a speaker below my bike and characteristic by no skill had to attend. each and each state is diverse with operating a red. Virginia in basic terms lately allowed motorcycles to run a red after waiting 2 cycles (120 seconds).

Answer 9

Some are on timer, some are triggered by a plate under the asphalt.

Answer 10

the majority of traffic lights are activated by a metal sensor under the road, just near the traffic lights.