M25, Variable Limits

[Nigel Worc's]

Generally one isn't enough they need two, but that aside, IF, and it is a big if, having different limits on each lane is actually legal and not just made up by the HA because they are trying to be clever s, then having no sign lit above a lane must mean that lane defaults to NSL.

Or can they really have their cake and eat it ?

[Landshark]

Nigel Worc's said:

Generally one isn't enough they need two, but that aside, IF, and it is a big if, having different limits on each lane is actually legal and not just made up by the HA because they are trying to be clever s, then having no sign lit above a lane must mean that lane defaults to NSL.

Or can they really have their cake and eat it ?

I'm guessing they are enjoying their cake?!


7. There was no speed limit show­ing above my lane, so the national speed limit applied, even though other lanes had over­head signs show­ing a lower limit.

Pro­vid­ing a valid manda­tory speed limit is prop­erly dis­played for the car­riage­way (not nec­es­sar­ily over each indi­vid­ual lane), that limit will apply to all lanes.

http://www.highways.gov.uk/our-road-network/managi...



Although this does now beg the question about whether they should have multi limits on one carriageway??

[Red Devil]

FWIW I have yet to see gantry signs where the figure displayed within the red ring is not the same on all lanes (I am not saying it's impossible - I just find previous claims on here to that effect hard to credit). If the HA website is to be believed then there wouldn't be any point in doing so anyway. How would the magistrates decide which figure was applicable? I very much doubt any prosecution would be brought and, if one were, any half competent motoring solicitor could get it thrown out.

[speedking31]

Asking for a printout from the control room does not help. That just shows what speed the operator / computer had set for each lane. If there is an electrical fault and the sign is not illuminated then the printout would probably not show that.

@Gafferjim: Does the system allow the operator / computer to set different speed limits for each lane? They obviously do permit different signals for move left or lane closed displays.

[Lawbags]

I'm not talking about different speed limits across lanes, I've seen on numerous occasions a limit being shown on 2-3 of the lanes, and the sign showing nothing above others.

[s p a c e m a n]

The only times that I have seen differing limits per lane on a gantry is when approaching a junction and signage and road markings are showing that there will be a split in the carriageway, so in effect they are different speed limits for different roads.

I agree that if there is a blank sign above a lane on a carriageway when one or more show a reduced speed you'll struggle to wriggle out of it because you only need one sign for the whole carriageway, otherwise the big single matrix boards would only be able to enforce the hard shoulder

[mygoldfishbowl]

Gantries & the whole system & whoever operates these things = Not fit for purpose.

Edited by mygoldfishbowl on Thursday 2nd October 21:22

[lbc]

Lawbags said:

I'm not talking about different speed limits across lanes, I've seen on numerous occasions a limit being shown on 2-3 of the lanes, and the sign showing nothing above others.

I have seen this on the M42 also.

When it rained on the M42, it was often was the case that the variable speed limits were not working at all, so traffic used to move much faster.

It was as if the variable speed system did not work in the rain and looked like dodgy electrics.

[knitware]

There are variable speed limits on the M6 triggered in certain situations. The limits are displayed on overhead gantries and when speed limits are displayed cameras become operational; these are also situated on the gantries.

A few months ago whilst traveling on the M6 south I saw an unfortunate chap, I’ll call him a chap but it could have been a lady, get flashed and there was nothing he could do about it.

As I was driving south I happened to glance onto the north bound traffic and I saw the gantry sign signal 50 mph just as a car was going under the gantry and as he popped out the other side he was flashed by a camera.

As far as he knew it was national speed limit and I’ve wondered ever since if he’ll have to pay the fine and collect points. It’s quite unfair but I’d hope surely someone in the ‘ticket office’ would take a look at the timings and scrap the ticket.

[CGJJ]

Has anyone ever actually received an NIP from any gantry camera on the M25
(Not including variable speed limits at roadworks or at the Dartford crossing?).
I have never heard of anyone.

[Geekman]

Just thought I'd bump this thread as it looks like they've finally switched them on.

http://forums.pepipoo.com/index.php?s=c3541512e68c...

http://forums.pepipoo.com/index.php?s=c3541512e68c...

[greygoose]

Geekman said:

Just thought I'd bump this thread as it looks like they've finally switched them on.

http://forums.pepipoo.com/index.php?s=c3541512e68c...

http://forums.pepipoo.com/index.php?s=c3541512e68c...

40mph limits on roadworks on motorways seem more frequent nowadays, it does seem very slow particularly in the night when no one is working there.

[DaveCWK]

Geekman said:

Just thought I'd bump this thread as it looks like they've finally switched them on.

http://forums.pepipoo.com/index.php?s=c3541512e68c...

http://forums.pepipoo.com/index.php?s=c3541512e68c...

How does this work when the matrix signs are not all displaying the same thing? I travel on the west section regularly past Heathrow and have seen the odd sign appear corrupted, or only 2 of the 4 displays on the gantry showing blank while the other 2 display a limit, etc.

Could a defence not be mounted based off the apparent unreliability of the system? Maybe I should start taking screen grabs from the dashcam of abnomalities...

[nipsips]

Looks like Ive got one coming then. Lane 4 on the south part of the M25 heading west, traffic moving at around 60mph quite safely. Speed sign said 60mph, next sign says 30mph. No one else does it, and I'm not stamping on the brakes in traffic doing 60mph to slow down to 30mph for no reason - especially in lane 4. I've passed a driving test, I can tell I can stop in the distance I can see and that its safe. What would they rather I did, cause a massive accident?

If it means points and a fine, lets see what happens!

[Blakewater]

The speed limit applies to all the lanes even if it's only displayed over some.

[Nigel Worc's]

Blakewater said:

The speed limit applies to all the lanes even if it's only displayed over some.

And if you have different limits over adjacent lanes on the same carriageway ?

[The Mad Monk]

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.

That should be 45mph, Shirley?

[Blakewater]

Still all of them. If it says 50mph over lanes 1 and 4, for example, you still have to stick to 50mph in lanes 2 and 3.

[The Mad Monk]

Speed Badger said:

Just to reiterate,

That is an iteration, not a reiteration.

[Nigel Worc's]

Blakewater said:

Still all of them. If it says 50mph over lanes 1 and 4, for example, you still have to stick to 50mph in lanes 2 and 3.

And if it says 20 over lane one, 30 over lane two, 40 over lane three, & 50 over lane four ?