Fixed *and* Averge Speed Cameras -- M4 J 7-6 -- or Generally

[Jared_Lumas]

Are there fixed speed cameras as well as average speed ones on the M4 between junctions 7 and 6 (eastbound)? Is having both commonplace?

I was driving along when a variable speed limit of 40 kicked in. I slowed down right away but when I went under the next couple of gantries there appeared to be a double-flash. I'm 99% sure I wasn't speeding but my eyes weren't glued to the speedo the whole time so you never know.

It occurred to me afterwards that I don't actually know if there are fixed speed cameras on the gantries as well (the average speed ones have been there for years). There were a lot of lights in general so I wondered if maybe some were obscured briefly in quick succession which looked like flashing. That probably sounds silly but I am so sure I wasn't speeding. So I thought knowing if there are fixed speed cameras or not could put my mind at rest.

Thanks.

[ResQ1]

Yes, they are fixed speed cameras on the gantry's at the side of the motorway in addition to the average speed cameras.

They work off the variable speed limits and are set to trigger at excess speed. I think you'll need to wait for 14 days to find out for sure if they caught you.

Edited by ResQ1 on Monday 17th October 13:32

[BertBert]

ResQ1 said:

Yes, they are fixed speed cameras on the gantry's at the side of the motorway in addition to the average speed cameras.

They work off the variable speed limits and are set to trigger at excess speed. I think you'll need to wait for 14 days to find out for sure if they caught you.

Are you sure that there are average speed cameras in operation in the variable speed limit zone? Aren't the av cams just left over from the roadworks?

[anonymous-user]

BertBert said:

ResQ1 said:

Yes, they are fixed speed cameras on the gantry's at the side of the motorway in addition to the average speed cameras.

They work off the variable speed limits and are set to trigger at excess speed. I think you'll need to wait for 14 days to find out for sure if they caught you.

Are you sure that there are average speed cameras in operation in the variable speed limit zone? Aren't the av cams just left over from the roadworks?

That’s my suspicion but it’s hard to be certain.

There are fixed+Ave cams on the M4 westbound from just past Heston services and the M1 southbound once you’re clear of the works that start just north of the A43.

If the average cams are working there would be no point in having the hadec3s. The fact that these newly re-opened bits of road now have gantries and hadec3 cams makes me assume that the ave cams have just been left there but are inactive. The absence of “average speed check zone” signs kind of reinforces that, but the absence of “camera not in operation” signs points the other way.

One thing is for sure though. It’s a great way to keep the traffic speed under control.


Eta: also hard to see how ave cams would work where the limit is set differently by successive gantries, unless the ave cams were right by the gantry - which they generally aren’t.

Edited by anonymous-user on Monday 17th October 14:56

[Greenmantle]

use this stretch every day.
obviously the Hadecs 3 are active.
I am assuming the average are as well otherwise how can they enforce the constant 60?

[BertBert]

Greenmantle said:

use this stretch every day.
obviously the Hadecs 3 are active.
I am assuming the average are as well otherwise how can they enforce the constant 60?

With the HADECS 3 perhaps? Although what do you mean by constant 60?

[livinginasia]

Goodness, so you could be fined twice for the same offence?

Does the world really need two sets of speed enforcement cameras on one road?

[BertBert]

livinginasia said:

Goodness, so you could be fined twice for the same offence?

Does the world really need two sets of speed enforcement cameras on one road?

No there are not two sets of active cameras and no you can't be fined twice for the same offence (in this case). Get a grip, even from Asia!

[Greenmantle]

BertBert said:

No there are not two sets of active cameras

Sorry how do you know that and which one is not active?
Hadecs 3 is a fixed point and not average speed camera.
The smart section of the M4 (J5 to J8/9) has always had the 60 mph on the signage and the vector system is still present.

[NMNeil]

livinginasia said:

Goodness, so you could be fined twice for the same offence?

Does the world really need two sets of speed enforcement cameras on one road?

All the time drivers ignore the posted speed limits...yes.

[BertBert]

Greenmantle said:

Sorry how do you know that and which one is not active?
Hadecs 3 is a fixed point and not average speed camera.
The smart section of the M4 (J5 to J8/9) has always had the 60 mph on the signage and the vector system is still present.

Because of the signage and use of common sense.
What does the signage say? A variable speed limit zone. No mention of av speed detection.
For common sense, how would the variable limit and the av speed detection work together. Any leftover av cams are not in the same places as the gantries changing the limit. The two systems would also have to be integrated to work.
And for the bold bit, what does that mean.? The new smart section is barely finished, so what does always had 60 mean? And what do you mean by the vector system?

[jvr]

It seems strange to me that it always seems to be 60 along there now even when the traffic is light, I can hear the tills ringing.
With regard to the average speed ones, I think they have been left there on purpose just to scare you but I must admit I don't know and taking the risk.

[BertBert]

You can chill. The AV speed cams and hadecs don't work together.