Just wondering what the score is with the camera’s on the gantry’s on the M25 just before the M4 exit as the overhead signs are setting very low speeds (30) on a clear motorway because there are roadworks on the M4.
Now I thought that the speed on the gantry is linked to a camera above and if you speed past it you’re caught but I seem to be the only one slowing down does everyone else know something I don’t? 
Now as far as I know the camera’s are set to a certain speed independant to the limit at the time. So for example the cameras on the gantry in question are set up for 40 mph and go live when the signs on the gantry also go to a 40 limit. When you pass through doing 45 mph youget flashed. If the limit is set to 50, the cameras are not active. The next set of cameras have a different speed limit, say 50, the next yet another, and so on. Don’t forget that not all the camera boxes have anything inside them either - ca 30% of them are actually empty…
I also know that they wanted to modernise this system a while back so that the camera is linked to the limit shown on the sign, but as far as I know the upgrade hasn’t been done yet…
i was told that they are permanently set at 70mph, as they never show any higher than 60mph on the board, even when its clear.
i have been thru there at 2/3 in the morning and they still show 60mph!
at the depot, we have had a “roadworks update” for the M25 for the start of next year, and the cameras will be set at 40 between the M40 and the M3 both carriageways when they start to put in the link roads to the new terminal 5 in February, and begin the widening of the motorway at the same time. they state that it will take about three years…hmmm!
Interesting
Just a couple of days out of date. 
SWEDISH BLUE:
Just a couple of days out of date.
Holy crap this thread is seventeen years old 
NelsonsCounty:
SWEDISH BLUE:
Just a couple of days out of date.Holy crap this thread is seventeen years old
And still going !! I wonder what is the oldest thread revival? And what was so interesting to robthedog??
Ok thanks I think I will play it safe though
I heard the following.
The cameras only work if 2 previous signs are showing the same limit, and they automatically set their trigger speed 10mph above the posted limit. If either ofthe 2 signs before it have different limits, then the cameras do not activate.
But they DO work, when they are set right.
If you’ve been through at 3 AM and they all show 60, then they will catch everyone over 70…
Ok Alli many thanks