Little black boxes above some traffic lights

aardvaak

Can someone please tell me what the little black boxes above some traffic lights are. I have seen them on some but not all lights on a roundabout?

Tallymanjohn

If they're the ones I'm thinking of, they are traffic sensors - you often also get them on temporary roadworks - they just sense when cars are waiting & the light sequence is altered accordingly - usually at night time when there's little traffic around. I guess they're cheaper than the ones usually buried under the road at normal junctions.

wdyw

Secret to them is not too get too close to them! So often I see people creeping right up to te white line and over and the mnever changing (for a right turn etc).

nearlyrich

I might be wrong but I think they are infra red sensors, some traffic lights are sequenced all the time others are set to the main flow with a sensor to indicate a waiting vehicle. They make my Snooper beep which is why I think they are infra red.

ollyshaw

I wish they were there to nab the growing number of people sneaking through on red at a pedestrian crossing!