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AIBU?

Share your dilemmas and get honest opinions from other Mumsnetters.

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Original poster

... to think that motorway overhead message signs are a complete waste of space

20 replies

ThePonderer · 05/08/2013 17:19

... and cause more problems than they save?

I spent the weekend mostly on the motorways of Britain, covering a good 500 miles, and not once did I see a sign that conveyed correct, helpful information.

Is there anything more irritating than being advised of a 40 mph speed limit when you are already stationary in a queue? Or slowing down for 'long queues ahead' when in fact that turns out to be the only part of your journey which is completely clear?

To me, they just seem to promote anxiety and irritation on the roads. I would rather have no information than have information that I can't trust to be up to date. AIBU to think they are useless?

OP posts:

babybythesea · 05/08/2013 17:22

We have a theory.

If it flashes up the normal speed limit sign, or 70, you're good and likely to go at the right speed.
If it flashes up 60, then you'll probably manage to do 50.
If it flashes up 50, you'll be down at 20 but at least still moving.
If it flashes up 40, then it's laughing at you, showing you an unattainable speed. "Ha ha - you think you'll get to do 40. Think again you're going NOWHERE!" It actually means stop.

lovecupboards · 05/08/2013 17:24

They're usually relatively accurate and helpful round my way.

Sirzy · 05/08/2013 17:26

The problem is they are not updated enough. Apparently we had an "animal in carriageway" for 3 days last years! Warnings like that could be useful if they were updated enough people paid attention.

The ones I don't see the need for are "caution fog" or "spray on road" - if you need signs to tell you that then please leave the motorway and head to a garage to sell your car!

ouryve · 05/08/2013 17:27

I'm sure DH could explain to you how they get their information, but the stuff responding to incidents is only as good as the people supplying the information and isn't necessarily in real time, iirc. The 40 is normally a warning so you don't hit the queue of traffic you're normally in at 70.

The stuff that tells you how long it takes to get to somewhere, is perfect, though. DH coded that :o

JADS · 05/08/2013 17:34

No they are terrible. The new ones on the M4 are particularly bad. They often show a 40mph speed limit despite there being being no accidents and light traffic. This means that generally they are ignored so that when it says "people on the road" everyone just carries on doing 70, slamming on the brakes when there is actually a bloke walking along the carriageway!

Yanbu, they are the boy who cried wolf of the sign world

WibbleBoy · 05/08/2013 17:54

Yeah, you're being unreasonable. The message signs (the ones with text) are triggered by a variety of sources, sometimes by directly linked sensors (fog), by calculating the time taken between points (time to xxx), by detected changes in traffic flow (delays), or by manual entry (accidents, concerts, diversions).

I could go into details about the process, but it would get very boring (as Yve can vouch), suffice to say that it's a very

Most of the time it runs smoothly, but the custom messages are set from a central location near Birmingham, typically based upon phone calls from police, local councils, etc. and sometimes people forgot to tell them stuff has cleared.

The signals (the speed ones) are typically set automatically when a problem is reported and are just there to try to slow down traffic in the lead up (for instance if there's an accident around a blind bend).

nannynick · 05/08/2013 17:56

The 15 miles to junction 4, 16 mins type sign is useful (thanks ouryve's DH) as it helps you to know the road ahead is running well.

Speed restrict signs would be ok if everyone did as they said. In actively managed sections the motorway controllers are trying to space out traffic so you don't get the stop start queue.

Heavy Rain Forecast was a sign I saw often yesterday, yet it did not rain on my journey. So not that useful.

RustyBear · 05/08/2013 17:56

I spent far too long on Saturday in a queue on the M4 caused by 'testing and commissioning' new signs. Except that nobody was. They'd just shoved a lot of cones down and buggered off for the weekend...

WibbleBoy · 05/08/2013 17:59

... I could go into details about the process, but it would get very boring (as Yve can vouch), suffice to say that it's a very complete process.

Hit the post button accIdentally (damn tablet).

;)

WibbleBoy · 05/08/2013 18:01

The speed ones aren't an actual restriction as such, they're just advisory. Unless they're surrounded by a red ring, in which case it's to be treated like a normal speed limit sign and you can get a speeding ticket if you ignore it.

tywysogesgymraeg · 05/08/2013 18:06

This is mine and DH's pet hate. I really don't need a sign which says "snow", when the drifts are feet high on either side if the road.
Nor do we need signs that say "don't drive tired" etc. People either drive tired or they don't. Signs won't stop you.

Itsnotahoover · 05/08/2013 18:41

I was faced with an amazing on the other week which, albeit briefly, announced ALL lanes were closed!!

The 40mph ones always strike me as being the cause rather than the effect; ie people stand on their brakes to slow down when they see the signs, yet I've rarely seen a reason for the speed limit to be low iykwim. Other than when completely stationary, when they are just there to taunt you!

purits · 05/08/2013 19:02

We have a bad one near us: after going up a gradient, there is a bend in the road and then the other side of the hill. The overhead is positioned just after the bend! Many motorists start to speed back up on the descent, see the sign and then slam on the anchors in panic.
The sign invariably says useless things like 'accident M25 jcn 4' - the M25 being about a hundred miles away.

Original poster

ThePonderer · 05/08/2013 19:03

It's true that the 'Time taken between points' info was all correct this weekend. (And reassuring).

None of the other signs were. WibbleBoy, I am prepared to believe that the system is very complex and I can see how it could be great, but in reality none of it seems to help much. If it's not up to date, it's not worth anything. How often would information be updated? How many people are there monitoring how many signs?

[Agrees with babybythesea's theory: 40 mph is posted just for a laugh. When you see it, you know it's going to be another hour to anywhere....]

OP posts:

iamadoozermum · 05/08/2013 19:08

Another thanks to ouryve's DH. The ones on the M6 help me to determine my route to work and back and they are always spot on. Give him a lovely of thanks from me .

The other sign info - well ...

WibbleBoy · 05/08/2013 19:16

The time estimates are usually quite accurate, but can also be out of date. The system runs from ANPR cameras; when cars pass between two cameras (say 10 miles apart) the time taken is used to update the sign (assuming the cars weren't speeding), but it's dependent upon the cars reaching the second camera.

If the second camera doesn't see any cars, or if the cars take a lot longer than they should, then the message switches to a "delay xx minutes".

Melawen · 05/08/2013 19:25

Those signs usually bug me hugely, but they did prevent us from joining a mega queue on the M25 when a crane crashed into the barrier. We got warning on the M4 before the Newbury junction and so Mum (passenger!) was able to double check the info on her phone and we detoured home via the A27 stopping for tea at my brother's place!

chateauferret · 05/08/2013 19:32

Round here they just spout general Transport Scotland nostra like "don't drive and debug Java servlets at the same time". Even when there's an accident five miles further on that they should be telling you about.

ouryve · 05/08/2013 19:39

I'll give him a squeeze from you, iam

WMittens · 05/08/2013 19:54

If it flashes up 60, then you'll probably manage to do 50.
If it flashes up 50, you'll be down at 20 but at least still moving.
If it flashes up 40, then it's laughing at you, showing you an unattainable speed.

Sorry, are you telling us that you think these signs are predicting the speed you'll be doing through the congestion?

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