Motorway gantry 'smart' messages...why wrong so often?
Discussion
Why, with so much money thrown at new technology capable of keeping us all safe (no laughing at the back) do we continue to see messages for something quite obviously not happening?
Today, on the M25 (shock!) we were faced with a single gantry red circled 40mph sign declaring "Queue ahead" You could see ahead. There was no queue. Nothing. It wasn't even busy.
The usual bunching up began to occur as some wondered whether to slow at all, others decreased speeds quickly, some had a half and half approach; undertaking, overtaking....all pointless.
Moments later and in clear view, the national speed limit sign.
15 to 20 mins after I passed, one of our other drivers came through the same section with it still lit. Still no queue, nothing in the distance, just the same single gantry lit with 40 mph and the warning.
It's not the first time, it won't be the last, but why? I understand it may be hard to pinpoint animals / small children / debris in the road type reports, but a blatantly obvious, non-existent queue?
Who is in charge of turning this stuff off?
Today, on the M25 (shock!) we were faced with a single gantry red circled 40mph sign declaring "Queue ahead" You could see ahead. There was no queue. Nothing. It wasn't even busy.
The usual bunching up began to occur as some wondered whether to slow at all, others decreased speeds quickly, some had a half and half approach; undertaking, overtaking....all pointless.
Moments later and in clear view, the national speed limit sign.
15 to 20 mins after I passed, one of our other drivers came through the same section with it still lit. Still no queue, nothing in the distance, just the same single gantry lit with 40 mph and the warning.
It's not the first time, it won't be the last, but why? I understand it may be hard to pinpoint animals / small children / debris in the road type reports, but a blatantly obvious, non-existent queue?
Who is in charge of turning this stuff off?
mattwhite709 said:
Ive thought this many times, its a lot more dangerous to slam on your breaks to get to 40mph for one gantry then it would be do the speed limit.
Or even your brakes.Gantry signs, and those alongside motorways, are to be ignored. For some reason they always appear to be required to display some banal message when they don't have anything relevant to show, as in the OP which clearly refers to a queue which was there several days ago. So they display something like "Think Bike" or "Don't drive tired" which apart from being completely meaningless detracts attention away from the business of driving.
As an alternative they display something which often happens at that particular location, even if it hasn't actually happened. So the lower reaches of the M3 on any weekday morning between 7 and 9am will have signs showing "Queue ahead" which will, naturally, result in a queue because drivers slow down expecting a queue.
If they showed messages saying "Don't drive like a complete retard" is it possible that driving standards might improve? Must be worth a try.
If we're doing this yet again (...sigh...), the usual - and generally entirely correct answer is that they are reacting to something several kilometres away which you will never see and which will have gone by the time you get there. They prevent fast traffic from running into the back of slowing traffic and try (and succeed, IMO) to keep traffic flowing.
littleredrooster said:
If we're doing this yet again (...sigh...), the usual - and generally entirely correct answer is that they are reacting to something several kilometres away which you will never see and which will have gone by the time you get there. They prevent fast traffic from running into the back of slowing traffic and try (and succeed, IMO) to keep traffic flowing.
and theyre not allowed to clear the gantry sign until someones been through and checked whatever the problem has cleared. That someone being part of an organisation with little resource to do the checkingOne day they'll discover google gives the flow information live for free
If the story was "I had no idea why the restriction was in place, and I turned off the motorway before I got to the end of it", then I would believe that it was reacting to some event miles away.
But 4 gantries going 60, 50, 40, NSL in quick succession? That's not some subtle traffic management plan, its just wrong.
But 4 gantries going 60, 50, 40, NSL in quick succession? That's not some subtle traffic management plan, its just wrong.
Generally when someone posts this sort of question, someone will pop up who says they work in the control centre and that the signs are always correct and we just don't understand that the system is working perfectly, we just can't see the accident/hold up/whatever that they are protecting us from.
Sadly, as I can fly an aircraft and my airfield is near the A1, I can see when the signs are spouting rubbish - people who have just arrived at the airfield as I land telling me the signs are warning them to slow down for queues/accidents/fog/whatever when I have just flown along the road and seen absolutely naff all.
Similarly, anyone posting about speedo over-reading will be told that GPS speeds are apparently not accurate and anyone doing 70mph on their GPS rather than sticking to the indicated 70mph on their speedo is actually breaking the law.
However, ask about the error ellipse on the GPS calculation and it all goes quiet.
Sadly, as I can fly an aircraft and my airfield is near the A1, I can see when the signs are spouting rubbish - people who have just arrived at the airfield as I land telling me the signs are warning them to slow down for queues/accidents/fog/whatever when I have just flown along the road and seen absolutely naff all.
Similarly, anyone posting about speedo over-reading will be told that GPS speeds are apparently not accurate and anyone doing 70mph on their GPS rather than sticking to the indicated 70mph on their speedo is actually breaking the law.
However, ask about the error ellipse on the GPS calculation and it all goes quiet.
littleredrooster said:
If we're doing this yet again (...sigh...), the usual - and generally entirely correct answer is that they are reacting to something several kilometres away which you will never see and which will have gone by the time you get there. They prevent fast traffic from running into the back of slowing traffic and try (and succeed, IMO) to keep traffic flowing.
So why a single 40 mph restriction, back to a national speed limit sign, all within ground covered in probably less than a minute? Within moments of braking to avoid a fine, you could see the national speed limit sign. How does any of that apply to what you suggest?rxe said:
But 4 gantries going 60, 50, 40, NSL in quick succession? That's not some subtle traffic management plan, its just wrong.
No, it's simply that you didn't see whatever had been between the 40 and NSL signs, causing the restriction to be put in place.Maybe it's not there any more, but nobody's had a chance to OK that yet.
Maybe you just didn't notice it.
Flooble said:
swisstoni said:
There's probably about 4 blokes trying to keep the whole crumbling edifice from crashing to the ground.
In other words, no money to support it properly.
Four? When did they get the budget to double their headcount??!In other words, no money to support it properly.
One in England, one in Scotland, one in Wales, one in NI.
TooMany2cvs said:
Flooble said:
swisstoni said:
There's probably about 4 blokes trying to keep the whole crumbling edifice from crashing to the ground.
In other words, no money to support it properly.
Four? When did they get the budget to double their headcount??!In other words, no money to support it properly.
One in England, one in Scotland, one in Wales, one in NI.
Google is your friend:
TL:DR - a lot of the limits are set automatically based on traffic speed and flow using sensor loops in the road.
Technology[edit]
The section of road subject to ATM is monitored by MIDAS sensor loops[3] placed in the road every 100 metres (328 ft)[4] (which is closer than normal)[5] to observe traffic flows.[4] A computerised system monitors the traffic flows and can set the best speed limit for the current flow of traffic and switch on speed limit signs mounted on gantries[6] up to 2 kilometres (1.24 mi) before an incident.[7] Operators can also monitor 150[8] CCTV cameras[9] along the route and can control both the speed limits and information signs.[6] Overhead variable message signs can direct drivers to use the hard shoulder during busy periods.[9]
When the speed limit has been lowered to 50 miles per hour (80 km/h) or below the hard shoulder can be opened as an additional lane.[10] To facilitate this and still maintain safety[5] a series of refuge areas have been created around every 500 metres (1,640 ft) along that stretch of the road.[2] These take the form of lay bys to the side of the hard shoulder and contain the SOS phones within them.[11] In the event of a vehicle breaking down on the hard shoulder, operators can close it or they can close a lane to allow emergency services access to an accident.[9] The hard shoulder is never opened on the sections under a junction between the off and on slip roads. Close to junctions use of the hard shoulder as a lane is restricted to traffic exiting or entering at that junction.[12]
ATM involves converting the hard shoulder into a normal lane during periods of high traffic flow to expand the capacity of the road[13] and may reduce the need to widen motorways.[13] Similar schemes have already been implemented in Europe.[8]
The system makes use of Automatic Number Plate Recognition cameras which to monitor traffic flows and tailor the system.[14] Digital enforcement cameras are also mounted on the gantries and are operated by the West Midlands Police to enforce the mandatory variable speed limits
TL:DR - a lot of the limits are set automatically based on traffic speed and flow using sensor loops in the road.
Technology[edit]
The section of road subject to ATM is monitored by MIDAS sensor loops[3] placed in the road every 100 metres (328 ft)[4] (which is closer than normal)[5] to observe traffic flows.[4] A computerised system monitors the traffic flows and can set the best speed limit for the current flow of traffic and switch on speed limit signs mounted on gantries[6] up to 2 kilometres (1.24 mi) before an incident.[7] Operators can also monitor 150[8] CCTV cameras[9] along the route and can control both the speed limits and information signs.[6] Overhead variable message signs can direct drivers to use the hard shoulder during busy periods.[9]
When the speed limit has been lowered to 50 miles per hour (80 km/h) or below the hard shoulder can be opened as an additional lane.[10] To facilitate this and still maintain safety[5] a series of refuge areas have been created around every 500 metres (1,640 ft) along that stretch of the road.[2] These take the form of lay bys to the side of the hard shoulder and contain the SOS phones within them.[11] In the event of a vehicle breaking down on the hard shoulder, operators can close it or they can close a lane to allow emergency services access to an accident.[9] The hard shoulder is never opened on the sections under a junction between the off and on slip roads. Close to junctions use of the hard shoulder as a lane is restricted to traffic exiting or entering at that junction.[12]
ATM involves converting the hard shoulder into a normal lane during periods of high traffic flow to expand the capacity of the road[13] and may reduce the need to widen motorways.[13] Similar schemes have already been implemented in Europe.[8]
The system makes use of Automatic Number Plate Recognition cameras which to monitor traffic flows and tailor the system.[14] Digital enforcement cameras are also mounted on the gantries and are operated by the West Midlands Police to enforce the mandatory variable speed limits
As mudash has highlighted in his Google search, the gantry signs are mostly controlled by systems outside human control. I wonder why better use cannot be made of this facility which spends around 80% of the time not being used.
For a start, why is the time not displayed on ALL of the signs as per Wales and France, amongst others. Why are the signs not used to display messages that should help to improve the driving standards of the sad people who drive as though they are the only people on the road. I'll start with a few suggestions:-
"DON'T HOG THE MIDDLE LANE(S)"
"THE SPEED LIMIT IN UK IS 70MPH"
"DO NOT USE A MOBILE PHONE WHILE DRIVING"
"DON'T DRINK AND DRIVE - EVER"
"DON'T TAKE DRUGS AND DRIVE - EVER"
"USE YOUR LIGHTS DURING BAD WEATHER"
"SEAT BELTS SAVE LIVES - USE THEM"
For a start, why is the time not displayed on ALL of the signs as per Wales and France, amongst others. Why are the signs not used to display messages that should help to improve the driving standards of the sad people who drive as though they are the only people on the road. I'll start with a few suggestions:-
"DON'T HOG THE MIDDLE LANE(S)"
"THE SPEED LIMIT IN UK IS 70MPH"
"DO NOT USE A MOBILE PHONE WHILE DRIVING"
"DON'T DRINK AND DRIVE - EVER"
"DON'T TAKE DRUGS AND DRIVE - EVER"
"USE YOUR LIGHTS DURING BAD WEATHER"
"SEAT BELTS SAVE LIVES - USE THEM"
Wills2 said:
They're utterly useless.....
Pedestrians in the road slow down!......no there isn't
Incident slow down!...............no there isn't
Animals on the road slow down!...............no there isn't
That was just a selection of the incorrect signs I've witnessed recently on the motorway.
But there may have been, several hours ago..Pedestrians in the road slow down!......no there isn't
Incident slow down!...............no there isn't
Animals on the road slow down!...............no there isn't
That was just a selection of the incorrect signs I've witnessed recently on the motorway.
Digby said:
Wills2 said:
They're utterly useless.....
Pedestrians in the road slow down!......no there isn't
Incident slow down!...............no there isn't
Animals on the road slow down!...............no there isn't
That was just a selection of the incorrect signs I've witnessed recently on the motorway.
But there may have been, several hours ago..Pedestrians in the road slow down!......no there isn't
Incident slow down!...............no there isn't
Animals on the road slow down!...............no there isn't
That was just a selection of the incorrect signs I've witnessed recently on the motorway.
Wills2 said:
They're utterly useless.....
Pedestrians in the road slow down!......no there isn't
Incident slow down!...............no there isn't
Animals on the road slow down!...............no there isn't
That was just a selection of the incorrect signs I've witnessed recently on the motorway.
Gaffer Jim is one to tell you about these signs as he works in a North West control centre. Pedestrians in the road slow down!......no there isn't
Incident slow down!...............no there isn't
Animals on the road slow down!...............no there isn't
That was just a selection of the incorrect signs I've witnessed recently on the motorway.
Pedestrians and animals move around, so when they're reported in an area a long stretch of road and both carriageways have to have the warning signs put up and speed restrictions put in place, be they mandatory speed restrictions on a smart motorway or advisory on an ordinary motorway. The pedestrians and animals may well just move away from the motorway but the police or Highways Agency officers have to check along the motorway to ensure the hazard has passed before the warnings and restrictions can be removed.
People will phone in to report things such as debris in the road, children dropping rocks off bridges or whatever else there might be but give the wrong section of motorway. People are rubbish at using the location markers on motorways to locate themselves in the event of a breakdown or to say where a problem on the motorway is. This means the warnings will be put in the wrong place or will have to be placed over a longer stretch of motorway than would be necessary if a specific location for the problem was given.
As an example, a friend of mine said his mother broke down on the M55 but told the RAC control centre she'd broken down on the M6. The two motorways merge a little further on from where she was. As the patrolman took a long time to find her she complained to the RAC about his incompetence.
A slow moving vehicle can be followed along a quiet motorway network as it, along with traffic slowing behind it, triggers lower speed limits.
The problem with a smart motorway is that, when a reduced speed limit is triggered by bunching and slowing traffic, the limit can only be switched off by the traffic speeding up. The same applies to an advisory limit on an ordinary motorway but on a smart motorway the traffic can't speed up because the limit is mandatory and speed cameras enforce it. The braking for the cameras creates a hazard in itself and causes the reduced speed limit to spread along the motorway, increasing a risk of accidents, and what is little to no problem becomes a very big problem.
While travelling northbound on the A1 in North Yorks recently I seen the overhead warnings signs were advising drivers to slow down because of an 'incident',a few miles later it turned out to be a rear end shunt and a couple of lanes were blocked,fair enough but what I couldn't get my head around were the overhead gantry signs displaying the same message for the next couple of miles AFTER the incident,and also traffic in the unaffected southbound lane being displayed the same message.
Theres also a mobile sign powered by a roadside generator on the A1 northbound near Gateshead which in the year that it has been there has never displayed any other message than 'please take your litter home',i wonder who is paying for that? and also wonder if whoever put it there has totally forgot about it.
Theres also a mobile sign powered by a roadside generator on the A1 northbound near Gateshead which in the year that it has been there has never displayed any other message than 'please take your litter home',i wonder who is paying for that? and also wonder if whoever put it there has totally forgot about it.
Edited by wildone63 on Sunday 26th June 21:15
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