I ask this because I was traveling on the M62 last week around Chain Bar when all of a sudden the next 4 matrix signs were set at 40mph just came on in a flash, no incident or obstruction as I could see all the way but then the 5th matrix sign was set back to the national speed limit.
This got me thinking do they do this sometimes just to get speeding fines? There was nothing there to warrant the 40mph just to come on out of the blue and obviously if you went through one where a camera is fixed you’d be looking at points and a fine and you can bet if you contested it in court you would get nowhere.
Same happened to me on the M5 last week.
There had been traffic around the M4 interchange and the signs read 40. The next one said 60, so I sped up and just as I got to it, it changed in front of my eyes to 40. I couldn’t slow down in time, so we’ll see what happens.
109LWB:
Same happened to me on the M5 last week.
There had been traffic around the M4 interchange and the signs read 40. The next one said 60, so I sped up and just as I got to it, it changed in front of my eyes to 40. I couldn’t slow down in time, so we’ll see what happens.
Them on the M62 work when there is no average speed limit set too, also on the M25. I’ve been travelling along and the cameras have been going off and flashing more times than they do at a film premiere in Leicester Square in London.
they have a time delay from the speed changing to the camera’s going active.
I once slowed down, and had to speed up again! What a flaming liberty.
We assume that the speed cameras on the new gantries of “managed motorways” automatically switch down from 70 to 40mph as soon as the signs start to flash? You get zapped if you go through at 41mph? 45mph? - or still set to trigger at 85mph?
Looking at how people tear past me down stretches of the road such as Shirley, M42 - suggest there that this isn’t the case.
Compare that to the clacket lane stretch or approaching Bell Common Tunnel clockwise M25 - the damned cameras are flashing off like the paperazzi at a red carpet! 
wildfire:
they have a time delay from the speed changing to the camera’s going active.
I read on here from a womble that there is a delay of approx 20-30 seconds before the cameras kick in at the lower speed.
Winseer:
Looking at how people tear past me down stretches of the road such as Shirley, M42 - suggest there that this isn’t the case.
Not all of the gantry’s on that stretch have a camera 
If there’s no camera on the other side there isn’t one on your side either
SteveBarnsleytrucker:
This got me thinking do they do this sometimes just to get speeding fines?.
Of course they do, how else are they meant to pay for thing like the annual police ball…?
DaiDap:
Winseer:
Looking at how people tear past me down stretches of the road such as Shirley, M42 - suggest there that this isn’t the case.Not all of the gantry’s on that stretch have a camera
The ones I see flashing off all the time at passing birds, etc. are the ones at the side of the overhead gantries
- NOT the ones above each of the 4 lanes looking down… Those are the ones that seem to trigger at 85mph regardless of what speed limit is shown on the signs…
When these cams first came about, like the ones around Heathrow on the 25, did seem to be set to 85 is regardless of the display. However, I’ve seen the ones on the M4 at Bristol and the M1 at Hemel go off for cars overtaking me at about 50ish when displaying 40
Wasn’t there a big “thing” about the M25 ones changing from a standard 85mph to variable in line with the signs? Last year sometime, IIRC?
I’m wondering if these overhead cameras will ever be used to enforce the DO NOT DRIVE IN RED ‘X’ LANE perps…
Who else is sick of plonkers driving up the inside through the closed lanes, and cutting in at the last moment when coning down to one lane? 
Winseer:
I’m wondering if these overhead cameras will ever be used to enforce the DO NOT DRIVE IN RED ‘X’ LANE perps…Who else is sick of plonkers driving up the inside through the closed lanes, and cutting in at the last moment when coning down to one lane?
AMEN to that! Also the pricks that don’t realise that the shoulder should only be used when a speed is displayed, the M42 is the favourite for that one.
I was told it is a 60 second delay from a reduced speed to enforcement
trubster:
Winseer:
I’m wondering if these overhead cameras will ever be used to enforce the DO NOT DRIVE IN RED ‘X’ LANE perps…Who else is sick of plonkers driving up the inside through the closed lanes, and cutting in at the last moment when coning down to one lane?
AMEN to that! Also the pricks that don’t realise that the shoulder should only be used when a speed is displayed, the M42 is the favourite for that one.
I was told it is a 60 second delay from a reduced speed to enforcement
So it’s not kinda “instant” like this example then? 
SteveBarnsleytrucker:
I ask this because I was traveling on the M62 last week around Chain Bar when all of a sudden the next 4 matrix signs were set at 40mph just came on in a flash, no incident or obstruction as I could see all the way but then the 5th matrix sign was set back to the national speed limit.
This got me thinking do they do this sometimes just to get speeding fines? There was nothing there to warrant the 40mph just to come on out of the blue and obviously if you went through one where a camera is fixed you’d be looking at points and a fine and you can bet if you contested it in court you would get nowhere.
I saw that on the M25 going round through Hertfordshire last week. They had 50mph speed limits and “Incident, slow down” all the way from the M1 to about halfway from London Colney to South Mimms. The only thing I could see was one broken down car on the hard shoulder (if that was it, why was it necessary to flag it up all the way back to Watford?) and then the limits went back to 70. They really should tell us the distance to the hazard, and if it’s a breakdown, perhaps they should close the nearside lane if it’s a 4-lane stretch, but it was a major overreaction.
SteveBarnsleytrucker:
I ask this because I was traveling on the M62 last week around Chain Bar when all of a sudden the next 4 matrix signs were set at 40mph just came on in a flash, no incident or obstruction as I could see all the way but then the 5th matrix sign was set back to the national speed limit.
This got me thinking do they do this sometimes just to get speeding fines? There was nothing there to warrant the 40mph just to come on out of the blue and obviously if you went through one where a camera is fixed you’d be looking at points and a fine and you can bet if you contested it in court you would get nowhere.
Happened to me in the same place - no obstruction or issues on the road, just a load of traffic travelling at 40mph for no apparent reason!!!
109LWB:
Same happened to me on the M5 last week.
There had been traffic around the M4 interchange and the signs read 40. The next one said 60, so I sped up and just as I got to it, it changed in front of my eyes to 40. I couldn’t slow down in time, so we’ll see what happens.
If you were driving in town (30 limit) and could see a 50mph limit sign 400 metres ahead, at what point would you accelerate to 50mph (assuming a clear road etc)?
Roymondo:
109LWB:
Same happened to me on the M5 last week.
There had been traffic around the M4 interchange and the signs read 40. The next one said 60, so I sped up and just as I got to it, it changed in front of my eyes to 40. I couldn’t slow down in time, so we’ll see what happens.If you were driving in town (30 limit) and could see a 50mph limit sign 400 metres ahead, at what point would you accelerate to 50mph (assuming a clear road etc)?
By the laws set you wouldn’t be able to accelerate to 50mph untill you pass the new speed limit sign… Well that’s what you should do