Anyone been done by one of these ?, I keep to the limit and other road users come past me all the time, So curious .
Yes.
Question was only asked on here a week ago, but for your benefit, I got a ticket off the average speed cameras on the A616 years ago for an average of 74 in a 60 - I’d been stuck behind a load of wagons for miles, got to the 1st 2 lane section, went past the lot of them, reaching around 120 - 130mph by the end of the 2 lane section - hence the average speed - and then dropped back down to 60, so I’d been doing 40mph through most, then 60 through the rest, and had an average of 74.
I sent it back arguing that I’d been behind these wagons for miles, and at the passing point it was safest to pass them all rather than try to squeeze in between them and got a ‘don’t do it again’ reply.
Barcelona_Karl:
Anyone been done by one of these ?, I keep to the limit and other road users come past me all the time, So curious .
Not yet, must have been close in my car once of twice, but I have no idea of the tolerance.
They speed past as do not know what average means and only brake when they see the camera then speed up again.
M5 around Bristol, the cameras are set for 57.6 mph. This is a fact NOT a MMTM
The 50mph ones I used to go through at full whack (which in my lorry is 59mph) with no problems. In the 40mph ones I once accidently went through one at 50mph before slowing down to 40mph with no problems.
One of our drivers got caught in the 40mph average speed check on the A23 in a van a few months back. I think he was doing 55 or something.
So in answer to your question: Yes they do catch people, but the tolerance is quite high.
SWEDISH BLUE:
M5 around Bristol, the cameras are set for 57.6 mph. This is a fact NOT a MMTM
As just posted, I used to do full whack through those at 59mph (indicated speed and satnav speed). Never got a ticket.
If it’s an average camera, then you can go past the first one too fast, and the second one too fast, but get away with it by dropping in the middle to even it all up.
I think the whole concept of average cameras as opposed to “snapshot” ones is that it allows punters to overtake in the roadworks (with the extra burst of speed needed) and gives you until the end of the leg to give it back.
A1234B
If you hit A doing 100mph, slow down to 40 by the time you hit 1, stay at 40 until you hit 2, accelerate to 60 to overtake for 3, and slow back to 40 for 4 and also finish off at B doing 40, then your average speed for the whole thing is not going to trigger the 50mph set average cameras. You don’t want to be doing a ton half way through though! 
Ched:
SWEDISH BLUE:
M5 around Bristol, the cameras are set for 57.6 mph. This is a fact NOT a MMTMAs just posted, I used to do full whack through those at 59mph (indicated speed and satnav speed). Never got a ticket.
Eh? Surely one of these “facts” is not?
I have been caught on these as well couple of years back M621 in to leeds average 55 in 40 limit 5am 60 quid and 3 points
As far as i’m aware, these cameras aren’t linked up in sequence.This was told to me buy the guy running the speed awareness course i recently attended. So for instance on a stretch with say 6 cameras, 1 and 4 might be connected, 2 and 6, 3 and 5 etc So if you are speeding though be carefull.
You could say they are designed to only get those who don’t at least go through the motions of slowing down once the roadworks start.
M25 6-5 is bloody annoying, because you’ll have some foreigner doing 50kmh in the middle lane, whilst you keep checking your 50mph on the hard shoulder being bounced around all over the place. Mustn’t be overtaking arschloch on the inside now must I? I’m more worried about getting a blowout from all the nuts, bolts, and other bits of metal debris that one finds on this dodgy bit of hard shoulder going past clackett lane services. 
BradCarTransporter:
As far as i’m aware, these cameras aren’t linked up in sequence.This was told to me buy the guy running the speed awareness course i recently attended. So for instance on a stretch with say 6 cameras, 1 and 4 might be connected, 2 and 6, 3 and 5 etc So if you are speeding though be carefull.
Then that would mean you could safely put your foot down at the last one before a slip road, and then the one on the slip road, not some thing i would like to test out!!
Winseer:
You could say they are designed to only get those who don’t at least go through the motions of slowing down once the roadworks start.M25 6-5 is bloody annoying, because you’ll have some foreigner doing 50kmh in the middle lane, whilst you keep checking your 50mph on the hard shoulder being bounced around all over the place. Mustn’t be overtaking arschloch on the inside now must I? I’m more worried about getting a blowout from all the nuts, bolts, and other bits of metal debris that one finds on this dodgy bit of hard shoulder going past clackett lane services.
I dont think its classed as under taking, unless you pull out in front of him, I pass loads of numpties doing less than 50 on the top end of the 25 road works.