RE: 50 limits by the back door: PH Blog
Discussion
fuelracer496 said:
This was explained in the previous article / thread. Traffic management and reduced speed limits are put in place when works are being carried out, often with revised lane geometry (plan alignment, lane width reduced, lane number reduced). Reduced lane widths can only be run at a reduced speed limit (often 50mph on motorways). This is a legal requirement due to Chapter 8 and other relevant traffic regulations.
In times where work isn't being undertaken, or at least you cannot see work being undertaken - it's safer and more cost efficient to leave the TM in place. It takes time to put it out and road workers are most at risk during the operation due to the requirement for them to be adjacent to a live lane.
No it's not. It's designed to catch people speeding and top up the government/council coffers.In times where work isn't being undertaken, or at least you cannot see work being undertaken - it's safer and more cost efficient to leave the TM in place. It takes time to put it out and road workers are most at risk during the operation due to the requirement for them to be adjacent to a live lane.
Mandown46 said:
The system is automated, monitored by sensors both in the ground, and recently radar at the side of the road. (the under tarmac loops involving a lot or roadworks to fix when they go wrong)
This system is better than it was a few years ago, and is continually being improved with new technology. Yes, as one of the (insert your preferred insult here) operators in the control room it is incredibly frustrating when you check CCTV to see why a speed has triggered, and its down to a abload, or some truck crawling up a hill, I don't know if they will ever solve that.
Mandown, thanks for the informed response, its great to get some balance on this topic. Dan, you should definitely make time to see how this works from 'the other side'.This system is better than it was a few years ago, and is continually being improved with new technology. Yes, as one of the (insert your preferred insult here) operators in the control room it is incredibly frustrating when you check CCTV to see why a speed has triggered, and its down to a abload, or some truck crawling up a hill, I don't know if they will ever solve that.
Unfortunately for me, I have been a heavy user of the M42 3a to 9 for longer than I care to remember and I would agree without doubt that journey times during peak hours are quicker and smoother since the introduction of smart lanes.
What I find incredibly frustrating are seemingly pointless restrictions outside of peak hours. For example, very recently at 22:00, very light traffic, no road works, dry, great visibility. Still there are sections set randomly to 60,50 or 40, than back up to NSL for what appears to be no reason at all. You have touched on it above, perhaps a very slow moving vehicle has been detected and triggered a restriction.
It would be great to get a better understanding of how and why this sort of thing occurs, I'm sure people would more readily accept that it is a limitation of the technology rather than the alternative which seems to be to conclude that the operator has gone to get a coffee, whilst continuing the journey with a blood pressure problem.
funkyrobot said:
fuelracer496 said:
This was explained in the previous article / thread. Traffic management and reduced speed limits are put in place when works are being carried out, often with revised lane geometry (plan alignment, lane width reduced, lane number reduced). Reduced lane widths can only be run at a reduced speed limit (often 50mph on motorways). This is a legal requirement due to Chapter 8 and other relevant traffic regulations.
In times where work isn't being undertaken, or at least you cannot see work being undertaken - it's safer and more cost efficient to leave the TM in place. It takes time to put it out and road workers are most at risk during the operation due to the requirement for them to be adjacent to a live lane.
No it's not. It's designed to catch people speeding and top up the government/council coffers.In times where work isn't being undertaken, or at least you cannot see work being undertaken - it's safer and more cost efficient to leave the TM in place. It takes time to put it out and road workers are most at risk during the operation due to the requirement for them to be adjacent to a live lane.
If youve been on the M5 you'll see a sign between two sets of roadworks with 'speed limit kept in place for safety'
'eck as like
Somewhere else you'll read how much money is raised in the stretch
saaby93 said:
funkyrobot said:
fuelracer496 said:
This was explained in the previous article / thread. Traffic management and reduced speed limits are put in place when works are being carried out, often with revised lane geometry (plan alignment, lane width reduced, lane number reduced). Reduced lane widths can only be run at a reduced speed limit (often 50mph on motorways). This is a legal requirement due to Chapter 8 and other relevant traffic regulations.
In times where work isn't being undertaken, or at least you cannot see work being undertaken - it's safer and more cost efficient to leave the TM in place. It takes time to put it out and road workers are most at risk during the operation due to the requirement for them to be adjacent to a live lane.
No it's not. It's designed to catch people speeding and top up the government/council coffers.In times where work isn't being undertaken, or at least you cannot see work being undertaken - it's safer and more cost efficient to leave the TM in place. It takes time to put it out and road workers are most at risk during the operation due to the requirement for them to be adjacent to a live lane.
If youve been on the M5 you'll see a sign between two sets of roadworks with 'speed limit kept in place for safety'
'eck as like
Somewhere else you'll read how much money is raised in the stretch
Motormatt said:
What I find incredibly frustrating are seemingly pointless restrictions outside of peak hours. For example, very recently at 22:00, very light traffic, no road works, dry, great visibility. Still there are sections set randomly to 60,50 or 40, than back up to NSL for what appears to be no reason at all. You have touched on it above, perhaps a very slow moving vehicle has been detected and triggered a restriction.
Had this at ~22:30 one night ~3 years back on the way back from Birmingham Airport. 50/50/60/50/40/50/60/50 (or something very similar) On an EMPTY motorway. At one point I could see no other car on the southbound carriageway ahead or behind.We'd had a long flight (with a toddler), we just wanted to get home, and "the system" had f'd up somehow, requiring me to concentrate on each gantry as I approached it rather than just look ahead and drive home quietly at a sensible speed.
Now I'm sure Mandown will claim it was a glitch, but this is one of those frustrating-for-absolutely-no-reason stories you share, and we've been surprised by the number of "me too" responses we've had from friends and colleagues...so some glitch...
Mandown46 said:
Dan, I'm somewhat disappointed.
Last time this was raised, one of my fine colleagues took the time to explain in detail how these work, and made you an offer to get you into the control room, and would have probably been able to get you some time out with the on road patrols too.
He had done this before for groups of PH'ers.
I remember discussing it in private with you as well.
I can only assume you didn't take him up on this, only to see you repeating the rant again is frustrating.
.
OK, riddle me this. Last time this was raised, one of my fine colleagues took the time to explain in detail how these work, and made you an offer to get you into the control room, and would have probably been able to get you some time out with the on road patrols too.
He had done this before for groups of PH'ers.
I remember discussing it in private with you as well.
I can only assume you didn't take him up on this, only to see you repeating the rant again is frustrating.
.
Quite regularly, very late on a Sunday night I join the M25 at Junction 15, heading towards 16. It is about 11 PM, traffic density is about 1 car per 500 meters in the three LH lanes, outside lane is empty.
All is good.
Suddenly in the distance, I see a 60 on a gantry. Oh dear, there must be a jam. Then a 50. Then .... back to NSL.
I've been on the stretch of motorway from start to finish of the event, there is no jam, no debris, no fog, nada.
Forgive me for believing this is either:
1) A cynical money making exercise
2) Utter incompetence in the technical implementation.
I'm sure there are benefits when the roads are really busy and you're trying to smooth traffic. However, randomly nicking people when the roads are empty is unhelpful....
Oddball RS said:
What next 'Did you leave the gas on?' 'Have you paid for your daughters school dinners this week?' How long before we get the first sponsored signs with ads on when not in official use?
I've had exactly this thought process myself.My favourite potential ones would be 'Eat Your Greens' or 'Avoid Crashing'. In terms of advertising what is 'M6 Toll Clear' all about? I want to know if the normal M6 is clear or not.
Just utter rubbish aren't they?
I use the M60 every day and I'm now on adaptive cruise set at 50 and don't really care any more, I will continue to drive like this after the road works finish and just allow an extra 5 mins journey time.
Aphex Twin on the stereo and knowing I'm getting a running average >50mpg helps
B.
Mandown46 said:
2. there's rarely enough operators to watch everything all of the time.
Is that because of financial constraints, lack of trained operators generally or ill health' holidays etc?If it's down to financial reasons; how much does one major accident cost in resources to attend, make safe or save, record all the evidence and clear up? Then how much does it cost each driver (or their employers) sat in stationary traffic for hours waiting for a road to open?
Simple (and cold) answer seems to be £1,323880.00 for a fatality down to £15,380.00 for a 'bump' (2003 figures)
http://www.freedomfordrivers.org/What_Does_a_Road_...
So how many more operators would the saving of one fatal accident provide for a better service with more coverage and why aren't we expanding it to make it safer and freer flowing when the financial, let alone human cost for every accident is so much higher?
Edited by cookie1600 on Thursday 30th March 10:58
Edited by cookie1600 on Thursday 30th March 10:58
saaby93 said:
That may be true too
If youve been on the M5 you'll see a sign between two sets of roadworks with 'speed limit kept in place for safety'
'eck as like
Somewhere else you'll read how much money is raised in the stretch
If you say so, but the stretches of motorway (on the M5) which I've been involved with had cluster schemes on the go where it was more efficient and safer to have continual TM on between each bridge location. To explain this (again):If youve been on the M5 you'll see a sign between two sets of roadworks with 'speed limit kept in place for safety'
'eck as like
Somewhere else you'll read how much money is raised in the stretch
Traffic management can only be put out when traffic flow is low enough, hence the requirement for night works a lot of the time. If you're lucky the TM might go on at about 9pm. It takes a while to put it out as the length of cones, advanced signage etc is time consuming. At the end of the shift, cone off needs to have taken place before 6am - so a night shift doesn't allow you much time to undertake works.
Schemes done under bridge clusters are often for foundation repairs, and as mentioned previously, have to be run with narrow lanes as the cofferdam surrounding the foundations needs to be wide enough to get temporary propping and hydrodem lances in to remove defective concrete. We've been pushed to reduce these to 1m surround as we don't want to upset road users.
When the bridge foundation outline itself is already sat under the hard shoulder, there's no choice but to run narrow lanes with a 50mph limit. On top of that, you require space to navigate plant in between the traffic side of the excavation and the temporary VRS installed between the workforce and the road user. There isn't another way to do it - most of the bridge schemes have a 48 week programme, and we've been 24/7 shifting one of them to accelerate the scheme for early completion. You cannot do that if you're spending time taking down and reinstalling TM each and every day during the construction phase.
When you're stood in lane 3 of a motorway repairing an expansion joint in the middle of the night, with just a line of cones along the lane 2 / 3 line and 50mph limit (that's never adhered to by the travelling public) and you hear the sound of cones being hit, you soon take the situation seriously. I guess we all have different agendas - the safety of operatives who have to walk out into a live lane to place cone tapers for the installation of a lane reduction, is quite important to some. Others just want to get to their destination quicker.
The systems clearly cost a lot to introduce. The cost analysis will show long term savings due to the highly automated operation of the systems. Like most modern automated systems the smart motorway is actually super dumb. To avoid problems the dumb motorway system will always choose the lowest speed when there is any doubt.
Slower is safer.
No account is taken from efficiency benefits due to higher speeds.
It is the UK where health and safety is priority number 1, 2 and 3.
And the classic comment "if you don't speed then you have nothing to worry about"
...will that still be heard when the motorway speed limit is 30mph?
Slower is safer.
No account is taken from efficiency benefits due to higher speeds.
It is the UK where health and safety is priority number 1, 2 and 3.
And the classic comment "if you don't speed then you have nothing to worry about"
...will that still be heard when the motorway speed limit is 30mph?
Hackney said:
Just as they're coming to the end of the roadworks south of the M6 junction another section starts from J23 to J25
Pretty much my entire regular journey (J13 to J24 or J27) will be on managed motorways or roadworks. Brilliant.
As per another thread, the problem is people who speed and then brake hard for the gantries (regardless of whether there's a camera or not)
I have lived in the loughborough area for over 10 years now and have need to travel both south and north on the M1 frequently. Mostly my time is between the M18 junction and J15 in Northampton. I have never known a time where that piece of road didn't have road works on it. Pretty much my entire regular journey (J13 to J24 or J27) will be on managed motorways or roadworks. Brilliant.
As per another thread, the problem is people who speed and then brake hard for the gantries (regardless of whether there's a camera or not)
I know stuff has to be done. Roads need mending, capacity needs improving; the new setup at J19 for M6/A14, whilst its taken an age, is actually quite good the few times I have used it. But I just wish they'd do it quicker or do it more efficiently. I cannot reconcile the need to have miles and miles of cones when they have about 3 guys and an excavator doing some work on 50 yd stretch. Its just unnecessary. They can't work on 10 miles of motorway at once (or at least I have never seen them do it, be it night or day) so why do they cone off such distances?
CupMeister said:
I agree 100% we've recently had a stretch of the M4 in Newport converted and there doesn't seem anything smart about it at all. The system is contrived creating a traffic density that just wouldn't exist with out the limits imposed. It often results in cars packed nose to tail and very little space for motorists trying to join from junctions. Now, I understand the idea behind the concept and with the Brynglas tunnels in Newport causing a natural bottle neck it's a sound enough idea. As with many of these things it's the execution that's lacking, and a good deal of fine tuning and no small amount of common sense could improve things massively.
Personally I think modelling is partly to blame. People in offices, miles away from the action, doing traffic models and using the output to guide improvements. Trouble with models is they often don't reflect real life. They're certainly not going to reflect the often irrational decisions many of the car driving public seem to make all too regularly. Kawasicki said:
The systems clearly cost a lot to introduce. The cost analysis will show long term savings due to the highly automated operation of the systems. Like most modern automated systems the smart motorway is actually super dumb. To avoid problems the dumb motorway system will always choose the lowest speed when there is any doubt.
Slower is safer.
No account is taken from efficiency benefits due to higher speeds.
It is the UK where health and safety is priority number 1, 2 and 3.
And the classic comment "if you don't speed then you have nothing to worry about"
...will that still be heard when the motorway speed limit is 30mph?
So a higher speed limit is more efficient? The following items would need to be addressed if the end goal was a higher speed limit, to increase the network throughput:Slower is safer.
No account is taken from efficiency benefits due to higher speeds.
It is the UK where health and safety is priority number 1, 2 and 3.
And the classic comment "if you don't speed then you have nothing to worry about"
...will that still be heard when the motorway speed limit is 30mph?
- Barriers: These would need to be replaced. As a minimum an N2 W5 system is designed for a 70mph limit. A new barrier design would be needed, which would go beyond a mere post centres change. The purpose of a steel barrier is to absorb the force of a vehicle and reduce its chances of rebounding back into the carriageway. Stiffer barriers require stronger edge beams on bridges. The majority of the 1970's designed bridges would require deck strengthening works. The set-back to barriers would increase (in line with the standard for how they're designed). Central reserve concrete barriers would need to be looked at also. Every single linear metre of barrier that's installed on every motorway would need this.
- Lining & road studs: Rib line widths, lane line widths and gaps are sized for the roads they cover - 70mph as it is. This would need to be changed - longer lines, longer gaps, new road stud placement.
- Signage: This would need to be replaced; from driver location signs to large ADS signs, they are all sized to be read at 70mph. They would have to be larger is an increased speed limit was introduced.
chrisga said:
I think smart motorways are the equivalent of traffic lights on roundabouts. Complicating the simplest things with technology to try to control the proles, despite the fact that when left to our own devices we have shown we can actually cope.
I pass over a number of larger roundabouts controlled by traffic lights on my commute and very occasionally the traffic lights are broken. I can usually tell when this is as there are no queues approaching them because everyone has sorted themselves out and just got on with using the rules of the road.
The ever changing limits on smart motorways seems to cause people to brake at gantries regardless of limit and bunch up to stop people lane changing. It seems to me more often than not when the limits on the same stretch of road are off, everyone just goes about their business and get on with driving to the conditions. The worst bit about smart motorways near me is that they have occasional hard shoulder running. Which catches loads of people out. When its off people are in the hard shoulder and when its on people don't go in it in case its off, or just for the next junction etc etc. And then if there is ever an incident when hard shoulder running is on none of the emergency services can get there easily as the hard shoulder is blocked too. Just leave well alone. I'd wager the M40 runs smoothly above the average national speed limit for the majority of the time with none of this smart nonsense and people manage fine.
Traffic lights on roundabouts can work if the roundabout is big enough and the phasing is done right. The one at J24 has to have lights as they built a little shortcut for people coming off the A50 and going towards the airport on the A453. They don't have to go round the roundabout anymore but consequently end up cutting across the main ring twice. There is only one entry point without lights out of 6, no prizes for guessing which one doesn't have huge queues of cars backed up on it. But its not so bad really, its managed about as well as it can be.I pass over a number of larger roundabouts controlled by traffic lights on my commute and very occasionally the traffic lights are broken. I can usually tell when this is as there are no queues approaching them because everyone has sorted themselves out and just got on with using the rules of the road.
The ever changing limits on smart motorways seems to cause people to brake at gantries regardless of limit and bunch up to stop people lane changing. It seems to me more often than not when the limits on the same stretch of road are off, everyone just goes about their business and get on with driving to the conditions. The worst bit about smart motorways near me is that they have occasional hard shoulder running. Which catches loads of people out. When its off people are in the hard shoulder and when its on people don't go in it in case its off, or just for the next junction etc etc. And then if there is ever an incident when hard shoulder running is on none of the emergency services can get there easily as the hard shoulder is blocked too. Just leave well alone. I'd wager the M40 runs smoothly above the average national speed limit for the majority of the time with none of this smart nonsense and people manage fine.
Worse is when they put them on tiddly little roundabouts like the one on Epinal way in Loughborough just outside the University. Lights on all entrances/exits, lights part way round, yellow boxes. Its always a grind. And when you get a HGV trapped on there it all just falls apart. The students don't help either, constantly hitting the crossing on at least two sides and constantly jamming traffic (they should have installed a footbridge or subway or something). On a number of occasions they have turned the lights off and monitored what happens. Usually the result is traffic that flows like water. So armed with this information they thought it would be a great idea to put traffic lights on the roundabout at the other side of the campus!!! (down the road from this one basically) and to boot, didn't remove already existing crossings so some exits/entrances have two crossings within feet of each other! I swear someone in the council gets kick backs for traffic lights.
Mandown, I wasn't aware HE were trialling radars, can you share any more info about it? Just wondering about where they'll mount them, how they'll deal with occlusion and things, quality of the length data etc.
As a bit of an insight for you guys, here's a screenshot from a page on our website (branding removed in case I'm accused of advertising!)
That data comes in every minute, and you can see how 'spikey' it is with regards to average speed. Obviously all of those blobs are traffic counters (in road loops). The system then uses this information to control the signage. Given how spikey this is, there must be some smoothing implemented, else the signs will be changing constantly and won't be effective...
But any sort of smoothing makes the system less responsive to a real issue. Say you wait for 5 minutes of low average speed before deciding it's definitely a real jam and not just 1 person merging badly causing a slow down. Well now the system sends 5 minutes worth of drivers (easily 700 vehicles) merrily on into the back of the jam up ahead...
It really isn't just that everyone involved in the traffic industry is a blithering idiot, honestly!
As a bit of an insight for you guys, here's a screenshot from a page on our website (branding removed in case I'm accused of advertising!)
That data comes in every minute, and you can see how 'spikey' it is with regards to average speed. Obviously all of those blobs are traffic counters (in road loops). The system then uses this information to control the signage. Given how spikey this is, there must be some smoothing implemented, else the signs will be changing constantly and won't be effective...
But any sort of smoothing makes the system less responsive to a real issue. Say you wait for 5 minutes of low average speed before deciding it's definitely a real jam and not just 1 person merging badly causing a slow down. Well now the system sends 5 minutes worth of drivers (easily 700 vehicles) merrily on into the back of the jam up ahead...
It really isn't just that everyone involved in the traffic industry is a blithering idiot, honestly!
fuelracer496 said:
If you say so, but the stretches of motorway (on the M5) which I've been involved with had cluster schemes on the go where it was more efficient and safer to have continual TM on between each bridge location. To explain this (again):
Traffic management can only be put out when traffic flow is low enough, hence the requirement for night works a lot of the time. If you're lucky the TM might go on at about 9pm. It takes a while to put it out as the length of cones, advanced signage etc is time consuming. At the end of the shift, cone off needs to have taken place before 6am - so a night shift doesn't allow you much time to undertake works.
Schemes done under bridge clusters are often for foundation repairs, and as mentioned previously, have to be run with narrow lanes as the cofferdam surrounding the foundations needs to be wide enough to get temporary propping and hydrodem lances in to remove defective concrete. We've been pushed to reduce these to 1m surround as we don't want to upset road users.
When the bridge foundation outline itself is already sat under the hard shoulder, there's no choice but to run narrow lanes with a 50mph limit. On top of that, you require space to navigate plant in between the traffic side of the excavation and the temporary VRS installed between the workforce and the road user. There isn't another way to do it - most of the bridge schemes have a 48 week programme, and we've been 24/7 shifting one of them to accelerate the scheme for early completion. You cannot do that if you're spending time taking down and reinstalling TM each and every day during the construction phase.
When you're stood in lane 3 of a motorway repairing an expansion joint in the middle of the night, with just a line of cones along the lane 2 / 3 line and 50mph limit (that's never adhered to by the travelling public) and you hear the sound of cones being hit, you soon take the situation seriously. I guess we all have different agendas - the safety of operatives who have to walk out into a live lane to place cone tapers for the installation of a lane reduction, is quite important to some. Others just want to get to their destination quicker.
As someone else who works in a similar field I can support this explanation (but I'm sure most people will ignore it and continue on their rants...)Traffic management can only be put out when traffic flow is low enough, hence the requirement for night works a lot of the time. If you're lucky the TM might go on at about 9pm. It takes a while to put it out as the length of cones, advanced signage etc is time consuming. At the end of the shift, cone off needs to have taken place before 6am - so a night shift doesn't allow you much time to undertake works.
Schemes done under bridge clusters are often for foundation repairs, and as mentioned previously, have to be run with narrow lanes as the cofferdam surrounding the foundations needs to be wide enough to get temporary propping and hydrodem lances in to remove defective concrete. We've been pushed to reduce these to 1m surround as we don't want to upset road users.
When the bridge foundation outline itself is already sat under the hard shoulder, there's no choice but to run narrow lanes with a 50mph limit. On top of that, you require space to navigate plant in between the traffic side of the excavation and the temporary VRS installed between the workforce and the road user. There isn't another way to do it - most of the bridge schemes have a 48 week programme, and we've been 24/7 shifting one of them to accelerate the scheme for early completion. You cannot do that if you're spending time taking down and reinstalling TM each and every day during the construction phase.
When you're stood in lane 3 of a motorway repairing an expansion joint in the middle of the night, with just a line of cones along the lane 2 / 3 line and 50mph limit (that's never adhered to by the travelling public) and you hear the sound of cones being hit, you soon take the situation seriously. I guess we all have different agendas - the safety of operatives who have to walk out into a live lane to place cone tapers for the installation of a lane reduction, is quite important to some. Others just want to get to their destination quicker.
Mandown46 said:
The system, in theory, should never show a 30mph from NSL, the lowest it should go is to 40mph direct from NSL.
Where speeds lower than 40mph are needed, the gantries should 'count down' on the gantry from NSL, a few seconds later 60, then 50 and so on. The gantries prior will also display a lead in, ideally slowing traffic down in plenty of time.
You might be able to help with a question I raised earlier in the thread. Do you know if there's a delay between the speed limit signs turning on, and the cameras working? (If you passed under a gantry at the exact moment the speed limit sign illuminated, would you get flashed?)Where speeds lower than 40mph are needed, the gantries should 'count down' on the gantry from NSL, a few seconds later 60, then 50 and so on. The gantries prior will also display a lead in, ideally slowing traffic down in plenty of time.
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