Safe Speed Forums

Hi there Im new to this forum and was wondering if anyone could tell me if the small boxes above traffic lights are traffic light cameras or just sensors? I have tried looking this up on various sites but could not find a clear anser thanks.

If you are talking about the small black boxes which have what looks like small infra red detectors, then yes, they are sensors to detect the movement and distance of vehicles on the approach to the lights.
Stephen

do they act as a recording camera device as well?

Nah.

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Paul Smith
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cheers thanks alot thats a big help

Yep, all they do is detect the presence of vehicles. I believe they all operate using radar, so will be detected by radar detectors. That obviously confuses some people.

If you stand behind them you'll see a little red light which comes on when it detects something. Then it turns off again.

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Andrew.

excellent I always wondered what they actually did and now I know, you learn a new thing everyday.

do you mean the big round one with an amber and green underneath?

cos it always goes on when i approach a set of lights

Ah that can happen too. Especially on signalised roundabouts and anywhere in Southampton.
But the little red light would come on first.

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Andrew.

They operate in the x-band at about 10 gigahertz. They used to use a gunn oscillator mounted in a small cast aluminium "horn" antenna. They are also used to detect pedestrians, cyclists etc. They produce an output depending on both presence and speed, so they can "count" vehicles passing in front of them.

According to my bosses radar detector some use K band.

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Andrew.