What would you do if you saw a 20mph variable speed limit on a motorway?

Seems to be a case of somehow improving and then proving that the system works and can be trusted. How many times do you see signs left out after the problem has abated, or signs go up with no sign of an actual problem.

When a system has the appearance that it's activated on the whims of a bored operator and/or bad software compliance tends to be lower than needed.

Personally don't use many parts of the smart motorway network but any time a gantry on a regular one is warning of problems I see if my satnav and general flow of traffic corroborates. If everything is moving as normal why be the thing that causes the problem by obeying.
 
.:MBK:. said:
Seems to be a case of somehow improving and then proving that the system works and can be trusted. How many times do you see signs left out after the problem has abated, or signs go up with no sign of an actual problem.
Click to expand...
Had a perfect example of this on the M6 last week, 40mph limit for a good few miles, info sign then comes up "Stranded vehicle", next sign "lanes 2 and 3 closed", next sign a mile a most after the closed lane sign "End". With no sign of anything anywhere.

Plenty of times I'm driving down the M54 first thing in the morning and the signs are saying the same thing they have been for the last 3 days.
 
.:MBK:. said:
Seems to be a case of somehow improving and then proving that the system works and can be trusted. How many times do you see signs left out after the problem has abated, or signs go up with no sign of an actual problem.

When a system has the appearance that it's activated on the whims of a bored operator and/or bad software compliance tends to be lower than needed.

Personally don't use many parts of the smart motorway network but any time a gantry on a regular one is warning of problems I see if my satnav and general flow of traffic corroborates. If everything is moving as normal why be the thing that causes the problem by obeying.
Click to expand...
Every time I've seen speed limits imposted by smart motorways, the gantry with a camera ALWAYS displays a slower speed than the ones without.

So, if all the others are 50, the camera gantry will be 40.
 
Burnsy2023 said:
What would you think was going on? Would you do anything other than reduce your speed? Do you know the circumstances in which a 20mph limit would be imposed?
Click to expand...
Being in Wales for one..

Other then that, as the thread has already unfolded.. I'd slow down expecting something quite hazardous, but then we share the roads with idiots, so no surprise when people ignore it.
Bug One said:
Every time I've seen speed limits imposted by smart motorways, the gantry with a camera ALWAYS displays a slower speed than the ones without.

So, if all the others are 50, the camera gantry will be 40.
Click to expand...
Interesting, I'll check the next time I'm going by Bristol on the M5 when its busy, they tend to step down the speed limits on the managed section, and not given it any thought.
 
.:MBK:. said:
Seems to be a case of somehow improving and then proving that the system works and can be trusted. How many times do you see signs left out after the problem has abated, or signs go up with no sign of an actual problem.

When a system has the appearance that it's activated on the whims of a bored operator and/or bad software compliance tends to be lower than needed.

Personally don't use many parts of the smart motorway network but any time a gantry on a regular one is warning of problems I see if my satnav and general flow of traffic corroborates. If everything is moving as normal why be the thing that causes the problem by obeying.
Click to expand...
Feek already explained the logic behind this....
Feek said:
Just because you don't see what caused the initial signs, doesn't mean there wasn't something ahead. You can be slowed down some considerable distance ahead of an incident to reduce the amount of traffic that arrives at the same time and to stop you grinding to a halt ten miles down the road.

They don't just turn those signs on to annoy people, they're done for a reason.
Click to expand...
Feek said:
Surely the point is that you have no way whatsoever of knowing if there's a reason. If you're slowed down fifteen miles from an incident to delay your time reaching that incident and having to stop in a queue, but that incident is cleared before you get there then there's a very good chance but you'll never know what it was. The temporary speed limit has done exactly what it's supposed to. It'll appear to you as though you were slowed down without a reason.
Click to expand...

The idea that there are operators who are sitting in control rooms who start imposing speed limits purely because they are bored, or to have a laugh at the expense of motorists, must surely count as one of the more mundane conspiracy theories :p
Don't get me wrong, "smart motorways" are on the whole a bad idea, but the traffic monitoring/variable limits aspect of them seems quite a sensible approach to traffic management. But they only work if people obey them, which no one does because "I never see a problem."
 
For the most part, the "regular" variable speed limits are set by a computer system based on sensors in the road. There isn't a human setting the limits until/unless the road conditions get beyond the parameters it is designed to operate in.
 
I got a speeding ticket the other day for doing 60 in a 50 on a smart motorway with a digital sign showing 50. I drive this motorway 4-6 times a week, and a few years ago I drove it everyday of the week.. to say I know it well is an understatement. At least 2 times a week there is a limit on the digital signs with no notification on a following sign that the limit has ended..the other digital signs following on are blank. This happened to me on the M25 last week as well. On the occasion I got a ticket there was a 50 limit for around 12 miles.. for seemingly no reason. No traffic, no accidents, no bad weather, nothing stranded.. again this happens on an almost weekly basis. Half way through the limit section, a sign was blank.. so almost everyone started speeding up, like me assuming it was finished. The next sign is round a corner.. It seems I didn't slow down fast enough for it.

When there is a obvious reason for a limit there is always a description of why shown on the signs.. e.g, stranded vehicle, lane closure ahead, congestion etc. Whenever there is not a sign saying national limit again, the previous signs never have a description why there is a limit in the first place.

According to the highways agency you should ignore any digital sign that doesn't have anything displayed and must always wait for the national speed limit sign to be posted as "there will always be one" = well there isn't, all the time.

I got offered a speed awareness course.. which i will take because I have no evidence there was a sign with nothing displayed and there is a picture of me driving my car at 60 through a 50 sign. But I have put in a freedom of information request to the highways agency about why there was a limit, how many signs are not working / reports of it etc. Once I get a reply I'm writing to my MP and anyone else who will listen.

In my mind it's completely unacceptable to have speed cameras on smart motorways when they clearly don't work correctly.
 
Last edited:
redeye said:
I got a speeding ticket the other day for doing 60 in a 50 on a smart motorway with a digital sign showing 50. I drive this motorway 4-6 times a week, and a few years ago I drove it everyday of the week.. to say I know it well is an understatement. At least 2 times a week there is a limit on the digital signs with no notification on a following sign that the limit has ended..the other digital signs following on are blank. This happened to me on the M25 last week as well. On the occasion I got a ticket there was a 50 limit for around 12 miles.. for seemingly no reason. No traffic, no accidents, no bad weather, nothing stranded.. again this happens on an almost weekly basis. Half way through the limit section, a sign was blank.. so almost everyone started speeding up, like me assuming it was finished. The next sign is round a corner.. It seems I didn't slow down fast enough for it.

When there is a obvious reason for a limit there is always a description of why shown on the signs.. e.g, stranded vehicle, lane closure ahead, congestion etc. Whenever there is not a sign saying national limit again, the previous signs never have a description why there is a limit in the first place.

According to the highways agency you should ignore any digital sign that doesn't have anything displayed and must always wait for the national speed limit sign to be posted as "there will always be one" = well there isn't, all the time.

I got offered a speed awareness course.. which i will take because I have no evidence there was a sign with nothing displayed and there is a picture of me driving my car at 60 through a 50 sign. But I have put in a freedom of information request to the highways agency about why there was a limit, how many signs are not working / reports of it etc. Once I get a reply I'm writing to my MP and anyone else who will listen.

In my mind it's completely unacceptable to have speed cameras on smart motorways when they clearly don't work correctly.
Click to expand...

Sounds to me like you're throwing your toys out of the pram because you got caught speeding.

Regardless of whatever the reason the variable speed limit was in place for, it still has to be abided by. Normally I'll see more than the one NSL sign to indicate back to normal speed, so if you weren't sure, it wouldn't be long before coming across another matrix sign.
 
Sounds like they've got you bang to rights on that one but I do agree there's plenty of times where they just start going blank with a NSL sign never to be seen so you've got no idea what you're supposed to be doing.
 
tom_e said:
Sounds like they've got you bang to rights on that one but I do agree there's plenty of times where they just start going blank with a NSL sign never to be seen so you've got no idea what you're supposed to be doing.
Click to expand...

Indeed they do, which is why i've accepted it because I was doing 60 through a sign that said 50.. not arguements there. If there wasn't a speed awareness course I would have paid the fine and points and accepted it to.

My entire post however is about not knowing what you should be doing because the signs simply aren't consistent. If there wasn't a break in the digital signage and there was an end to the temporary limit and it being a one off, I'd have no issue other than it being annoying to have a limit for so long for seemingly no reason. But as my post says, it happens ALL the time.

squerble said:
In my mind it's completely unacceptable to have people on the road who can't manage to read two-digit numbers correctly.
Click to expand...

No need for that, as explained above.
 
Last edited:
Most of the time they seem to be just a money collecting operation so I drive accordingly, whilst watching pretty much everyone else just sail past me ignoring the signs.
 
Shadowness said:
Forgive me if I've missed something
Click to expand...
you did, they aren't challenging the speeding ticket
squerble said:
In my mind it's completely unacceptable to have people on the road who can't manage to read two-digit numbers correctly.
Click to expand...
oh dear - if you're going to have a pop at someone, at least be correct. they slowed down to the speed the initial sign indicated so clearly they are quite capable of reading 2 digit numbers correctly.
 
redeye said:
No need for that, as explained above.
Click to expand...
Perhaps. But you say the sign was around the corner and you didn't manage to slow down in time. There's not a chance in hell that on a motorway the corner was so sharp to be completely obscuring the sign and not leave you enough distance to slow from 70 or less to 50mph. How fast were you going before you started braking for the limit?

I appreciate you're seeing an inconsistent (and annoying) nature in the signage, however your OP is just a misdirected vent when you somehow weren't able to slow down your car to a limit advertised on huge signage and should have had a speed differential of 20mph or less. I'm still of the not-so-humble opinion that you should be directing the anger at no-one other than yourself for what appears to be extremely poor control of your car.
 
Thekwango said:
you did, they aren't challenging the speeding ticket

oh dear - if you're going to have a pop at someone, at least be correct. they slowed down to the speed the initial sign indicated so clearly they are quite capable of reading 2 digit numbers correctly.
Click to expand...

Well corners aren't 90 degree bends on motorways. Still not hard to read 50 from a good distance away.
 
To be fair I've experienced the same with "smart" motorways and inconsistent or missing signage. I have no problem doing 50 when the signs say 50, but when the next gantry is completely blank am I OK to carry on at 50, or should I slow to 40? Mr HGV right up my **** seems to think its now NSL... the point is that the signs need to work, consistently, if they are going to issue fines based on them.

...and don't get me started on "Report of pedestrians". Has anyone ever seen any sign of a pedestrian when those signs are showing?
 
lordrobs said:
To be fair I've experienced the same with "smart" motorways and inconsistent or missing signage. I have no problem doing 50 when the signs say 50, but when the next gantry is completely blank am I OK to carry on at 50, or should I slow to 40? Mr HGV right up my **** seems to think its now NSL... the point is that the signs need to work, consistently, if they are going to issue fines based on them.

...and don't get me started on "Report of pedestrians". Has anyone ever seen any sign of a pedestrian when those signs are showing?
Click to expand...

Once, yes. A family walking up the hard shoulder. In dark clothing. At night. On an unlit stretch.
 
You must log in or register to reply here.
Back
Top Bottom