Motoring Discussion > Overhead gantry speed signs. again Miscellaneous
Thread Author: henry k Replies: 10

 Overhead gantry speed signs. again - henry k
Did a quick trip from J9 M25 through J8 at lunchtime in good weather and the traffic density was very very light.

Every single overhead gantry, and there are a lot of them, was showing 60 with no red ring around it in every lane (execept for one sign on one gantry over lane three that was not working.)
There were no vehicles crashed or even on the hard shoulder. No repairs being done, no giant loads and no wide loads.
At J8 the last gantry showed NSL signs.

What was all that about ???? No wonder these signs are so often ignored.
When will someone get a grip of sorting out the use /abuse of these signs?

rant over.
 Overhead gantry speed signs. again - a900ss
Funny you should post the as last night I was on the M4 and it had 50 signs on the temporary signs (no red ring, just a recommended speed). I could see no reason for the reduced speed nor did I see anything further on.

A plod car was in the middle lane doing 50. It wasn't a a traffic car, just a local Ford Focus estate.

Several cars slowed behind him and stuck at 50 but I went past at 70.

He didn't try to stop me but I did think what if? OK he can't do me for speeding but could he have been picky and tried for careless driving or a.n.other offence?
 Overhead gantry speed signs. again - Meldrew
I think that, for the posted limit to be legal it has to have the red ring round it. Odd that all the ones you saw had a number and no ring. If you had got a NIP it would be hard to prove that displayed limit sign was illegal!
Last edited by: Meldrew on Sat 29 Oct 11 at 07:49
 Overhead gantry speed signs. again - WillDeBeest
Paul Ripley in his Telegraph column once described the limits on matrix signs as 'mandatory', which surprised me at the time. If that were the case, would we have had the fanfare for the introduction of true variable limits on the M25 gantries?

That said, if you were to cause an accident, I imagine it would have to be taken into account by insurers, and maybe even the courts, that you were travelling above the recommended speed. In other words, they are not directly enforceable but ignoring them may still have consequences.
 Overhead gantry speed signs. again - Zero
>> I think that, for the posted limit to be legal it has to have the
>> red ring round it. Odd that all the ones you saw had a number and
>> no ring. If you had got a NIP it would be hard to prove that
>> displayed limit sign was illegal!

All the elements of the sign have to be lit before the camera will work, it has sensors to ensure this is the case.
 Overhead gantry speed signs. again - Meldrew
And do the cameras automatically default to the displayed limit Zero?
 Overhead gantry speed signs. again - Zero
When the limit is displayed correctly (number in red ring) the camera sets to that speed. There is a delay between number displayed (or changed) and camera armed at that speed.

Matters not what the number is or why, so even if its set in error, thats the speed limit.
 Overhead gantry speed signs. again - henry k
>> I think that, for the posted limit to be legal it has to have the > red ring round it.
That is my understanding
>>
Odd that all the ones you saw had a number and no ring.
>>
I think they are advisory only. I did not mention the four lights around each ome were flashing.
These warning signs are more often in the central reservation.

My point was that there were so many activated woth absolutely no apparent reason for it.
IMO the effect will be - ignore them until the reason becomes apparent, if it ever does.

 Overhead gantry speed signs. again - Focusless
I emailed the Highways Agency a few years ago after driving 20 odd miles down the M40 with a 50mph limit for no obvious reason:

"Thank you for taking the time to comment on our Variable Message Signs (VMS). The Highways Agency values the feedback we receive from the travelling public as this is our primary source of identifying how effective our signs are at keeping drivers informed.

VMS were turned on due to reports of debris in the carriageway. Due to several conflicting reports of the location of the debris, a number of VMS were set. In the interests of safety, the VMS have to remain on until it has been confirmed that all of the reported debris has been removed. Once confirmation is received the signs will then be switched off."

Perhaps something similar had happened in your case; email them?
Last edited by: Focus on Sat 29 Oct 11 at 09:34
 Overhead gantry speed signs. again - Zero
Must have been a wider problem yesterday.

11:00 most of the northern western side of the M25 (from 21 to 17) had END displayed on them.

The 60 signs started at J17, and went all the way to 11 where they dropped to 40.

The 60s at that time of the day are not unusual.
 Overhead gantry speed signs. again - Bromptonaut
The section of the M25 referenced in the OP is pretty short. Could the problem, real or vaguely, reported have been beyond the point where Henry left the motorway?

I know it's a PITA when these things come on for no apparent reason but all they're really saying is 'there may be trouble ahead'. A clue to watch out and be ready to react if brake lights start to appear. Perhaps devote a second or two to review alternative routes, aprticulalry if the matrix signs are giving dealy inforamtion.

If you don't see anything else carry on as normal. Even if you reduce speed to 60 it's hardly going to make you miss the next appointment.
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