What are the silver boxes on top of Traffic Lights ?

Answer 1

Traffic sensors that help move traffic.

Answer 2

If you look at them, they are generally angled to point somewhere far behind you - like about twenty cars back.

Loop sensors in the road detect approaching traffic and change the lights at fixed intervals to allow traffic flow. If a lot of traffic quickly approaches a set of lights, the silver box sensor picks up those cars at the back and overrides the normal time delay to allow this unusually high number of cars to move through the lights.

They are not speed cameras nor are they traffic monitoring cameras. They simply detect the build up in traffic and adjust the timing of the lights to accommodate the extra traffic.

The magnetic field from loops sensors would not very well that far from the lights. You will often see a grey box about 1.4 metres high near the traffic lights. This is a traffic light control box and it changes the lights depending on what all of the sensors pick up.

Answer 3

They are sensors that can detect headlights or flashing lights so that the lights change. Helps things like ambulances and also are used on roads that tend to be quiet which lead onto a busy road so that the lights only change to green for the quiet road when required...if that makes sense!

Next time you approach one try flashing your full beams a few times and the lights should change green quicker.

I know this works because I do it all the time!! During the day it may not work as it is harder to see the flashing but they do sense your indicators sometimes. But at night it most definately works - have done it many many times and the lights go green straight away instead of taking several mins!

Answer 4

They are radar detectors. During the day the lights are on a timer but when it gets after midnight and there is hardly any traffic about the radars will detect traffic and change quicker to allow the car through. As for the flashing your lights to make them change quicker is a total myth.

Answer 5

Movement detectors. if the lights are on red and have been for a while and nothing is coming the other way the lights will change in your favour. They replace the rubber strips you used to see before traffic lights because they last longer and are cheap[r

Answer 6

They are sensors that detect moving vehicles and change the lights when there is nothing coming the other way. There is also a time control in case the movement sensors do not work. Many people think they react to flashing headlights, but these are people who do not get out in the daytime when headlights are switched off. While they are sitting and flashing their headlights, two things happen
1. The lights change of their own accord because of the length of time.
2. Some fool interprets the flashing lights as a signal to go ahead and an accident happens.

Answer 7

Traffic cameras. Making sure that the traffic stops when the lights are on red.

Answer 8

I believe they are traffic monitors that count the amount of traffic using the junction and from which directions most cars travel. They can then adjust the lights accordingly. Be careful because some of them are cameras that book you if you jump the lights.

Answer 9

They can be two things , 1 is a movement sensor and 2 is a camera to catch red light jumpers

Answer 10

Movement sensors