M25, Variable Limits

Author
Discussion

walsh

Original Poster:

652 posts

158 months

Tuesday 30th September 2014
quotequote all
Hello,

I have always been under the impression that the speed camera's on the M25 don't trigger, unless there is a lower limit showing on the variable boards. I spend a lot of time (unfortunately) pottering around the M25, and I can't recall ever seeing one go off, Until Sunday.

Just after the Dartford tunnel, Cruising at 70 (ish), and the next Gantry shows a 50 limit, with a message showing "Pedestrians in road". Fair enough, Cruise off, Slow down the 50, Cruise on. A few others appear to follow suite, However most crack on at the speed they were traveling and a camera (next to the gantry, rather than on it) lit up like a machine gun. Must have been 15 cars traveling at 70ish. Cue lots of panic braking, etc. Next speed sign, back to national limit, I no pedestrians I could see.. But that's not the point.

Anyway, Questions are.

1) Is there a time period between the limit changing and when the camera's go off. I imagine they cant impose a 40 limit, then catch people from the second the signs change, or it would be carnage?

2) Have the camera's always worked, or have they changed it recently? I've not seen anyone get caught before, and people appear to sail through when if I have slowed, waiting for the limit to change back to national.

3) If they lower the limit for specific reason (As above), and you get caught, do they have to demonstrate there was a legitimate reason for the drop? The road was clear, and un-congested (for the M25 anyway.

I have always backed off, down the limit shown, rather than brake. As such, I have passed some of these well in excess of the posted limit, which I am starting to think might be very dim. For example, cruising speed ( lets be honest, 80ish), 50 limit comes up, So I will ease off, and move over. I have in the past passed these still doing 65-70ish I imagine, and could do without being caught 40% over the speed limit...

Cheers


SS2.

14,455 posts

237 months

Tuesday 30th September 2014
quotequote all
walsh said:
1) Is there a time period between the limit changing and when the camera's go off.
10 seconds.

walsh said:
2) Have the camera's always worked, or have they changed it recently?
They've been capable of (and approved for) enforcing NSL for years. Whether or not they are used for such is a matter of local policy.

walsh said:
3) If they lower the limit for specific reason (As above), and you get caught, do they have to demonstrate there was a legitimate reason for the drop?
No.

Adrian E

3,248 posts

175 months

Tuesday 30th September 2014
quotequote all
There is different kit in place on different sections of the M25 - the one you are referring to has only recently had roadworks removed after hard shoulder running was introduced and these new cameras off to the side of the gantries came into use. They have a fairly low threshold over the NSL even when reduced speed limits aren't in force. Other sections of the m25 seem to tollerate a higher travel speed when NSL applies, before they get excited.

The gantries are fairly obvious once you know what the new cameras look like but generally cruise control is the best option round that section and if they're displaying a lower limit it's best to stick pretty close to it.


Geekman

2,863 posts

145 months

Tuesday 30th September 2014
quotequote all
I've seen various gantries on the M25 flash loads of times, but so far nobody has reported getting a ticket.

Nigel Worc's

8,121 posts

187 months

Tuesday 30th September 2014
quotequote all

walsh said:
3) If they lower the limit for specific reason (As above), and you get caught, do they have to demonstrate there was a legitimate reason for the drop?
No.
And this is somewhat of a pisser.

Many many many times on the M42 variable limit section you see mile after mile of reduced limits, sometimes even varying limits, and no fooking reason at all.

These variable limits can of course be useful for keeping traffic flowing, but we are at the mercy of the fkwits in the control room to turn them off when they are not needed.

Landshark

2,117 posts

180 months

Tuesday 30th September 2014
quotequote all
Nigel Worc's said:
And this is somewhat of a pisser.

Many many many times on the M42 variable limit section you see mile after mile of reduced limits, sometimes even varying limits, and no fooking reason at all.

These variable limits can of course be useful for keeping traffic flowing, but we are at the mercy of the fkwits in the control room to turn them off when they are not needed.
Apart from the traffic flow bit is run by a f**kwit computer!!


Mr Will

13,719 posts

205 months

Tuesday 30th September 2014
quotequote all
Nigel Worc's said:
And this is somewhat of a pisser.

Many many many times on the M42 variable limit section you see mile after mile of reduced limits, sometimes even varying limits, and no fooking reason at all.

These variable limits can of course be useful for keeping traffic flowing, but we are at the mercy of the fkwits in the control room to turn them off when they are not needed.
I suggest you look up how they work. The idea is that they slow down the traffic for a significant distance prior to the congestion, allowing it to dissipate and you to continue through without encountering it. Your journey time will be the same, but instead of doing 80mph then slowing to 10mph you average 40mph across the whole stretch.

Speed Badger

2,667 posts

116 months

Tuesday 30th September 2014
quotequote all
Yes but it is a pain if the limit has been reduced simply to ease traffic flow and you get fined, rather than due to road works or an accident/hazard. Technically the motorway speed limit is 70 and one should be entitled to do 70 unless there is the aforementioned issues.

Just to reiterate, I have no problem with the traffic being slowed - those guys in the control rooms do a better job than we realise - it's the fining that gets me, there always seems to be some kind of bloody financial penalty for everything these days.

Oh and Mr.Will - you should see what would happen to the M25 if those fcensoredkwits weren't in the control rooms...

Edited by Speed Badger on Tuesday 30th September 16:16


Edited by Speed Badger on Tuesday 30th September 16:16

Mr Will

13,719 posts

205 months

Tuesday 30th September 2014
quotequote all
Speed Badger said:
Oh and Mr.Will - you should see what would happen to the M25 if those fcensoredkwits weren't in the control rooms...
Think you've got me and Nigel mixed up there...

Landshark

2,117 posts

180 months

Tuesday 30th September 2014
quotequote all
Speed Badger said:
Yes but it is a pain if the limit has been reduced simply to ease traffic flow and you get fined, rather than due to road works or an accident/hazard. Technically the motorway speed limit is 70 and one should be entitled to do 70 unless there is the aforementioned issues.

Just to reiterate, I have no problem with the traffic being slowed - those guys in the control rooms do a better job than we realise - it's the fining that gets me, there always seems to be some kind of bloody financial penalty for everything these days.

Oh and Mr.Will - you should see what would happen to the M25 if those fcensoredkwits weren't in the control rooms...

Edited by Speed Badger on Tuesday 30th September 16:16


Edited by Speed Badger on Tuesday 30th September 16:16
Technically the motorway speed limit is what ever the speed in the red rings says it is.

There are some motorways with permanent lower limits!

s p a c e m a n

10,752 posts

147 months

Tuesday 30th September 2014
quotequote all
Mr Will said:
I suggest you look up how they work. The idea is that they slow down the traffic for a significant distance prior to the congestion, allowing it to dissipate and you to continue through without encountering it. Your journey time will be the same, but instead of doing 80mph then slowing to 10mph you average 40mph across the whole stretch.
Yes but at 3am when a slow moving abnormal load with an escort is traveling through these sensors at 40mph it sets all of the gantries behind it at 40mph for miles and they take ages to reset themselves, so they plan these loads to travel at night to reduce congestion and then every vehicle for an hour has to travel at 40mph for several junctions.

Go automation thumbup

Landshark

2,117 posts

180 months

Tuesday 30th September 2014
quotequote all
s p a c e m a n said:
Yes but at 3am when a slow moving abnormal load with an escort is traveling through these sensors at 40mph it sets all of the gantries behind it at 40mph for miles and they take ages to reset themselves, so they plan these loads to travel at night to reduce congestion and then every vehicle for an hour has to travel at 40mph for several junctions.

Go automation thumbup
This is one of the downsides to a system that cannot be over ridden as well, another being when one or more gantries gets stuck on!! frown

Lawbags

1,047 posts

127 months

Tuesday 30th September 2014
quotequote all
I travel the M25 all hours of the night.
I've seen the 40 limits up when I'm the only car on the road and I sail through them at 85 and have never been flashed.

Nigel Worc's

8,121 posts

187 months

Wednesday 1st October 2014
quotequote all
Lawbags said:
I travel the M25 all hours of the night.
I've seen the 40 limits up when I'm the only car on the road and I sail through them at 85 and have never been flashed.
You have been very lucky, I'd suggest you don't take the same approach to other motorway variable limits !

Lawbags

1,047 posts

127 months

Wednesday 1st October 2014
quotequote all
Nigel Worc's said:
You have been very lucky, I'd suggest you don't take the same approach to other motorway variable limits !
Its mainly the M25 that gets it so wrong.
Ive not seen another empty motorway with 'congestion' signs up at 4am when Im the only car on the road.

robinessex

11,046 posts

180 months

Wednesday 1st October 2014
quotequote all
Reports in our local paper suggest that the M25 section from about J27 to the Dartford Crossing is now 'live' with respect to speed cameras functioning when the motorway managed system is ON, i.e. lower than 70mph is being displayed on the gantries. As well, speed enforcement approaching the crossing (BOTH SIDES), and on the crossing itself is now also live ALL THE TIME.

emmaT2014

1,860 posts

115 months

Wednesday 1st October 2014
quotequote all
robinessex said:
Reports in our local paper suggest that the M25 section from about J27 to the Dartford Crossing is now 'live' with respect to speed cameras functioning when the motorway managed system is ON, i.e. lower than 70mph is being displayed on the gantries. As well, speed enforcement approaching the crossing (BOTH SIDES), and on the crossing itself is now also live ALL THE TIME.
Well if the rest of the report is as accurate as the part I have highlighted it is all complete cock and without any reliable evidence whatsoever.

Landshark

2,117 posts

180 months

Wednesday 1st October 2014
quotequote all
Lawbags said:
Nigel Worc's said:
You have been very lucky, I'd suggest you don't take the same approach to other motorway variable limits !
Its mainly the M25 that gets it so wrong.
Ive not seen another empty motorway with 'congestion' signs up at 4am when Im the only car on the road.
This is as explained above, a slow moving load has gone through and confuses the computer making it think there is slow moving traffic hence the system reacts put up the reduced speeds and congestion warnings!!
It also happens when lanes are closed and work trucks park on the loops or pass over them slowly, the computer doesn't understand so reacts the way it's been programmed to!!!


walsh

Original Poster:

652 posts

158 months

Wednesday 1st October 2014
quotequote all
SS2. said:
walsh said:
1) Is there a time period between the limit changing and when the camera's go off.
10 seconds.

walsh said:
2) Have the camera's always worked, or have they changed it recently?
They've been capable of (and approved for) enforcing NSL for years. Whether or not they are used for such is a matter of local policy.

walsh said:
3) If they lower the limit for specific reason (As above), and you get caught, do they have to demonstrate there was a legitimate reason for the drop?
No.
Like it, thanks! 10 seconds it more than enough time to lose 20mph by backing off.

Nigel Worc's

8,121 posts

187 months

Wednesday 1st October 2014
quotequote all
Lawbags said:
Nigel Worc's said:
You have been very lucky, I'd suggest you don't take the same approach to other motorway variable limits !
Its mainly the M25 that gets it so wrong.
Ive not seen another empty motorway with 'congestion' signs up at 4am when Im the only car on the road.
Try the M42, West Mids area, I use both and reckon the Midlands crew could teach the London crew how to be complete cocks rather than part time.