What are the square boxes on the motorways/dual carriage ways just before or after bridges ?

Question

What are the square boxes on the motorways/dual carriage ways just before or after bridges ?

Answer 1

They're used to measure your speed. Basically, if a radar gun thinks you're speeding, just before you reach the box the camera will be triggered, and if you've gone past the box when the photo is taken (because there's a delay from when the camera is set off to when it goes off), then you're definitely speeding, as the police know the exact film speed (ISO) of their cameras, and how long it takes for someone who's not speeding to get to the box.

Answer 2

speeding markers

Answer 3

If you mean the boxes on brackets in the sides of bridges, they are checking the traffic speed for the trafficmaster congestion avoiding system. They don't measure individual identifiable vehicles

Answer 4

surveyors markings they are used to trigger sensors on the underneath of surveyors cars when checking journey time on major routes these can be circles,dots,pelicans(like on the crossings) and large squares

Answer 5

cops use em as markers for speeding...

Answer 6

Distance markers that police use to measure you speed.

Answer 7

These boxes are distance markers for the police they take an average speed between the markers and if your over 5% of the speed limit  for that piece of road expect a pull or a nasty letter through the post. Hope this helps P.S dont get caught.