My only concern with motorway cameras is the proving that the camera is set to trigger at the posted limit. In other words, if the posted limit due to conditions is 60mph, and you get flashed at 55mph, how would you prove that the posted limit at the time was 60 and not 50?

 

A dash cam.

 

I've just fitted one in my car for less than £60.

I doubt very much that your dashcam will trump a Home-Office type approved camera, whatever it shows. Unfortunately.

It will be enough to prove the matrix sign was showing 60mph though, so when the ticket arrives claiming that you were doing 55mph in a 50mph limit you can show that the sign said different.

I hope that they would accept that, I wouldn't bank on it.