Hadecs speed cameras

[johnnyroper]

With ever increasing sections of smart motorway appearing was just wondering if anyone knows if these cameras are operational all the time or just when speed restrictions are in place,and are they instantly activated when limit is changed?

On the M4 eastbound approaching M32 I think I may have been flashed when no restrictions in place and at a speed of 73ish,traffic was starting to build so might have had limit reduced as I passed under the sign

[Mirez]

Don't know much about the M4 ones yet but the M25 ones are active all the time. The trigger point was 100mph but I read somewhere it's being lowered to 90 soon.

It's highly unlikely to be set so close to the permitted limit just because of the tolerances generally given. The M25 ones give 10 seconds between displaying a speed limit and then the camerasite enforcing that speed and again I would expect the M4 ones to be similar.

[johnnyroper]

Oh right ok so in theory so long as not taking the p**s should be ok with them.

[KingyMAK]

I was told that unless there's a speed limit displayed, the cameras are not active.
All the 'Smart Motorways' are the same, especially since the massive M62 scandal that happened because of the same cameras.

You also have 30 seconds on the cameras as you should be able to slow to the needed speed in 30 seconds and keep the flow. (10 seems a little low!)

[insanitybeard]

I've been told that unlike some of the other stretches of 'smart motorway', the average speed cameras on the M5 between Avonmouth and the M4 interchange (Bristol area) are active all the time regardless of whether a lower speed restriction is displayed on the gantries, I can't vouch for this first hand but if this is the case, beware.........