RE: 50 limits by the back door: PH Blog
Discussion
last week used the M1 drove from Bristol to Leeds and back the next day.. ooohhh 50mph - 60 mph - speed cameras - roadworks - 50mph. etc etc so so many speed cameras, on all of the managed motorways (m42 as well) allowing for this easily added 30 mins onto journey each way by obeying speed limits. not to mention trucks going at 55mph in the 50 right up behind cars.
spent most of my time on the lookout for speed cameras instead of looking where I was going, that's modern driving I guess, but a pain in the a***
It's 4 lanes in places - so why do people still sit in the outside 2 or 3? doing the speed limit. another story,
rant over...
spent most of my time on the lookout for speed cameras instead of looking where I was going, that's modern driving I guess, but a pain in the a***
It's 4 lanes in places - so why do people still sit in the outside 2 or 3? doing the speed limit. another story,
rant over...
Terminator X said:
From behind a paywall site; I suspect a reasonable element of this is related to emissions and will drive down average speeds on such roads, see my bold below:
"The main reason for implementing a smart motorway solution is to enhance the capacity of the motorway without the cost and disruption of adding an additional lane. Most of the foundations and building work are already in place for the hard shoulder, so it is a question of converting from the hard shoulder format to lane format rather than adding an additional lane from scratch. As a motorway reaches more than 80% capacity, small changes in speed can ripple across the whole system due to minimal capacity to absorb the shock. When the smart motorway regulates the traffic to the same speed, there is less incentive to switch lanes, and traffic flows more smoothly, allowing for more cars per hour on the same stretch.
Investment in motorways has not kept up with demand in the past two decades, highlighted by relative per capita spending on roads; 75% higher in France and 40% higher in Germany than the UK in 2010. As a result the quality of the network has declined and congestion, noise and poor air quality are issues at numerous hotspots. Continued underinvestment is not an option as aging roads will increasingly fail to meet social, economic and environmental aspirations of the country.
The SRN [Strategic Road Network] is strategically important, making up only 2.4% of all roads, but carrying 33% of road traffic and 67% of all freight traffic. Significant growth in demand on these roads is expected by the Department for Transport (DfT)who forecast 44% growth between 2010 and 2035.
By 2040, DfT estimates that unless action is taken congestion will cost £10bn a year in lost time, and £2.2bn to the freight industry. The high growth scenario for the SRN would result in the loss of 16 hours per household to traffic each year, 28 million lost working days per year and an annual cost to the freight industry of £3.7bn by 2040. Difficulties presented by congestion on strategic roads could include:
Impeded travel between regions, which hampers business
Longer travel times, which constrain possible job opportunities
Poor journey time reliability impacting on business
Negative impacts on efforts to spur economic growth with enterprise zones, potential housing sites and areas of high growth held back by bottlenecks
Increased stress on roads to ports and airports making it harder for British businesses to access export markets
Safety and environment suffering as congested traffic is more polluting and there is an increased risk of accidents.
Smart motorway schemes have proven effective in responding to congestion and growing demand. A review of the M42 DHSR scheme around Birmingham found that it not only reduced congestion and improved journey time reliability, but also improved safety, with the frequency of accidents falling by more than half on the stretch. Smart motorways fall within the existing highway corridor, so do not usually require complicated planning processes as they fall within the existing development corridor, potentially saving years of delay and enquiry costs.
Environmentally, any addition of capacity is going to present some challenges, and the increased capacity could be expected to drive up air and noise pollution in the area. However, evidence from existing smart motorway schemes suggests no significant increase in noise and air pollution. This could be partially due to the reduction in speed and smoother flow of traffic resulting in lower emissions.
In addition to other benefits, smart motorways improve speed compliance (and hence safety) by controlling and managing motorways through the use of overhead mandatory speed limits, driver information, CCTV coverage and enforcement. Improved speed compliance reduces risk to users of the motorway, and any construction workers active on it.
The ability to inform drivers of unexpected conditions through the latest generation of roadside variable message signs also improves safety and provides further benefits to the smart motorways programme (SMP)."
TX.
The thing about emissions is, your car produces demonstrably more of them when accelerating. I hope to god someones done the maths and not just gone; reduce speed by 10 mph, reduce emissions by 5%. Job done, neglecting the fact people will speed up again once past the limits. Of course if the limits stop things grinding to a halt, then better. Emissions can be at their worst in stop-start."The main reason for implementing a smart motorway solution is to enhance the capacity of the motorway without the cost and disruption of adding an additional lane. Most of the foundations and building work are already in place for the hard shoulder, so it is a question of converting from the hard shoulder format to lane format rather than adding an additional lane from scratch. As a motorway reaches more than 80% capacity, small changes in speed can ripple across the whole system due to minimal capacity to absorb the shock. When the smart motorway regulates the traffic to the same speed, there is less incentive to switch lanes, and traffic flows more smoothly, allowing for more cars per hour on the same stretch.
Investment in motorways has not kept up with demand in the past two decades, highlighted by relative per capita spending on roads; 75% higher in France and 40% higher in Germany than the UK in 2010. As a result the quality of the network has declined and congestion, noise and poor air quality are issues at numerous hotspots. Continued underinvestment is not an option as aging roads will increasingly fail to meet social, economic and environmental aspirations of the country.
The SRN [Strategic Road Network] is strategically important, making up only 2.4% of all roads, but carrying 33% of road traffic and 67% of all freight traffic. Significant growth in demand on these roads is expected by the Department for Transport (DfT)who forecast 44% growth between 2010 and 2035.
By 2040, DfT estimates that unless action is taken congestion will cost £10bn a year in lost time, and £2.2bn to the freight industry. The high growth scenario for the SRN would result in the loss of 16 hours per household to traffic each year, 28 million lost working days per year and an annual cost to the freight industry of £3.7bn by 2040. Difficulties presented by congestion on strategic roads could include:
Impeded travel between regions, which hampers business
Longer travel times, which constrain possible job opportunities
Poor journey time reliability impacting on business
Negative impacts on efforts to spur economic growth with enterprise zones, potential housing sites and areas of high growth held back by bottlenecks
Increased stress on roads to ports and airports making it harder for British businesses to access export markets
Safety and environment suffering as congested traffic is more polluting and there is an increased risk of accidents.
Smart motorway schemes have proven effective in responding to congestion and growing demand. A review of the M42 DHSR scheme around Birmingham found that it not only reduced congestion and improved journey time reliability, but also improved safety, with the frequency of accidents falling by more than half on the stretch. Smart motorways fall within the existing highway corridor, so do not usually require complicated planning processes as they fall within the existing development corridor, potentially saving years of delay and enquiry costs.
Environmentally, any addition of capacity is going to present some challenges, and the increased capacity could be expected to drive up air and noise pollution in the area. However, evidence from existing smart motorway schemes suggests no significant increase in noise and air pollution. This could be partially due to the reduction in speed and smoother flow of traffic resulting in lower emissions.
In addition to other benefits, smart motorways improve speed compliance (and hence safety) by controlling and managing motorways through the use of overhead mandatory speed limits, driver information, CCTV coverage and enforcement. Improved speed compliance reduces risk to users of the motorway, and any construction workers active on it.
The ability to inform drivers of unexpected conditions through the latest generation of roadside variable message signs also improves safety and provides further benefits to the smart motorways programme (SMP)."
TX.
I am not holding my breath. It'll be like those renewable fuels where the return on energy invested ends up being upside down; good intentions, incompetent implementation.
Attilauk said:
big_rob_sydney said:
Mandown, one thing I just cant get my head around, is why the 50 limits apply for road workers, especially on Sundays, when most of the time, these guys arent even working?
What can be done about this???
The speed limits aren't there to protect those of us who work in the closures, if you are hit by 2+ tonnes of metal at 50mph you will be just as dead as if it was going 70...What can be done about this???
They are there for the safety of the general public using the roads. In narrow lanes where vehicles are that much closer to each other the reduced speed limit is there to compensate for this. The regulations are in place as a blanket to cover all road users, generally the type of people who post on a forum like this are better drivers by the pure fact that they are interested in driving. The regulations have to cover the type of person who has no interest in driving, it's just something that has to be done to get to work / go shopping / visit family etc.
To put it another way, when you have 10's of thousands of vehicles passing through your site every day you can't judge every single one on ability, you have to impose limits to cover everyone including the cockwombles...
However, what you've done is answer a question I didn't ask. Its all well and good to tell me about what happens when a road is narrowed. But that's not what I actually asked. Would you like to have another go, or perhaps answer another question that hasn't been asked? (I'll give you a hint; no road narrowing was mentioned)...
It's full! 
50 50 50. Animals in road 40 40 40 Animals in road. Ten miles later, Road clear- not an animal seen.
50 50 50, Queue ahead. 40 40 40 Queue ahead. Ten miles later, Road clear- not a queue in sight
50 50 50 Debris in road 40 40 40 Debris in road. Ten miles later, you've guessed it- no debris in road!
It's about time that the authorities could have fines levied against THEM for showing false information time after time.
Have seen such signs very late at night when traffic is light and any supposed queue disappeared hours ago.
Very frustrating to be forced into driving at a ridiculously slow speed for miles when it is blatantly obvious that signage is wrong.
50 50 50, Queue ahead. 40 40 40 Queue ahead. Ten miles later, Road clear- not a queue in sight
50 50 50 Debris in road 40 40 40 Debris in road. Ten miles later, you've guessed it- no debris in road!
It's about time that the authorities could have fines levied against THEM for showing false information time after time.
Have seen such signs very late at night when traffic is light and any supposed queue disappeared hours ago.
Very frustrating to be forced into driving at a ridiculously slow speed for miles when it is blatantly obvious that signage is wrong.
NomduJour said:
fuelracer496 said:
So a higher speed limit is more efficient? The following items would need to be addressed...
For a 10 mph increase, where all car traffic has already been doing 85-95 mph wherever possible for years in any case?My view; if the control freaks insist on massive speed limit enforcement (outside of times when flow control requires reduced limits) they already have evidence that to do so with an 80mph limit rather than 70mph will cause no difference whatsoever to anything... Except people can get about their day (fully grown-up adults / tax payers / parents etc) without fear of being penalised for nothing.
NomduJour said:
For a 10 mph increase, where all car traffic has already been doing 85-95 mph wherever possible for years in any case?
My point was that the current network was designed and built around a 70mph. I'm well aware that motorists take great pleasure in driving faster than that, but a highway network has to be built and maintained in accordance with the speed limit imposed upon it. If the speed limit for motorways was to be raised, legally all the points I raised in the post you part-quoted, would have to be addressed. Barriers in particular - they're approved for use based on specific criteria, namely the speed limit. If a driver were to be killed by ending up in a ditch / river as the result of hitting a parapet that was now sub-standard (under a raised speed limit), the ensuing investigation would likely find the managing agent at fault and there'd be a claim of manslaughter for not providing adequate protection for the road user.The managing agent is damned if they do, damned if they don't. You get whinged at for having road works in place to carry out repairs, refurbs and improvements, and you get whinged at for not maintaining the network when you don't.
There isn't much more for me to add; every year a similar article gets posted, and we go through the motions of explaining the issues, the problems with the supposed 'quick fixes' and hair brain ideas that people come up with - each time it falls on deaf ears and 12 months later another article appears and it becomes another misinformed rant about the state of the roads etc.
Dan, if you're still reading this - we can try and sort some sort of visit out for you, but it's likely to be later in the year as the contract down this end is coming to a close in June and it'd be easier to arrange something the other side of July when the dust settles and the new incumbent is up to speed.
Mandown46 said:
With debris signs, these are set only when debris has been confirmed, either a operator on CCTV his seen something, or another solid source has, ie a police officer, hato, roadworker has seen the debris. You will only see them in the immediate run up to the debris, usually the 2-3 signals prior to the debris. They will be removed only when the debris has been cleared.
M40 Southbound between Banbury and Oxford the Sunday before last at ~8.45am or so - there were ~6-8 MILES of matrix signs proclaiming debris in the road and flashing a 50 advisory limit.I decided, as it was quiet, sunny and excellent visibility, to ignore them and keep my eyes open, as did ~90% of other road users, presumably showing the same mix of distrust of the matrix signs (for crying wolf too often) and common sense.
Never saw any debris. Never saw a HATO or other hi-viz. How does that fit in with your guidance above?
I think the matrix signs are a GREAT idea that is being misused by an incompetent or agenda'd bureaucracy. Which is a real shame, as if drivers trusted them they'd be of far more benefit...
chris996 said:
50 50 50. Animals in road 40 40 40 Animals in road. Ten miles later, Road clear- not an animal seen.
50 50 50, Queue ahead. 40 40 40 Queue ahead. Ten miles later, Road clear- not a queue in sight
50 50 50 Debris in road 40 40 40 Debris in road. Ten miles later, you've guessed it- no debris in road!
It's about time that the authorities could have fines levied against THEM for showing false information time after time.
Have seen such signs very late at night when traffic is light and any supposed queue disappeared hours ago.
Very frustrating to be forced into driving at a ridiculously slow speed for miles when it is blatantly obvious that signage is wrong.
Could be that, in many cases, you never see the holdup or obstruction as it's gone by the time you get there, because you were going slower? Not trying to be a dick, but this possibility seems obvious to me whilst nearly everyone else seems to not heve ever considered it 50 50 50, Queue ahead. 40 40 40 Queue ahead. Ten miles later, Road clear- not a queue in sight
50 50 50 Debris in road 40 40 40 Debris in road. Ten miles later, you've guessed it- no debris in road!
It's about time that the authorities could have fines levied against THEM for showing false information time after time.
Have seen such signs very late at night when traffic is light and any supposed queue disappeared hours ago.
Very frustrating to be forced into driving at a ridiculously slow speed for miles when it is blatantly obvious that signage is wrong.
This question of design speed for motorways. My understanding was that the design speed is essentially one that is comfortable to travel and is related to alignments, road widths, etc. The connection between design speed and safe speed, which brings in the issues of accident statistics, is really rather tenuous, and IMHO to turn round and say design speed is x, and to shift a speed limit a few mph above that would need wholesale revision of the most minor details is frankly a bit silly. M62 east has a design speed of 90 for example.
FiF said:
This question of design speed for motorways. My understanding was that the design speed is essentially one that is comfortable to travel and is related to alignments, road widths, etc. The connection between design speed and safe speed, which brings in the issues of accident statistics, is really rather tenuous, and IMHO to turn round and say design speed is x, and to shift a speed limit a few mph above that would need wholesale revision of the most minor details is frankly a bit silly. M62 east has a design speed of 90 for example.
Not convinced the design speed is the speed limit eitherMandown46 said:
chris996 said:
50 50 50. Animals in road 40 40 40 Animals in road. Ten miles later, Road clear- not an animal seen.
50 50 50, Queue ahead. 40 40 40 Queue ahead. Ten miles later, Road clear- not a queue in sight
50 50 50 Debris in road 40 40 40 Debris in road. Ten miles later, you've guessed it- no debris in road!
It's about time that the authorities could have fines levied against THEM for showing false information time after time.
Have seen such signs very late at night when traffic is light and any supposed queue disappeared hours ago.
Very frustrating to be forced into driving at a ridiculously slow speed for miles when it is blatantly obvious that signage is wrong.
If you are seeing Animals in road shown, its because someone has called in (usually to the Police) that they have seen animals on or near the road, be it sheep, deer or dogs usually. We HAVE to put the signs on in case the animal does run into the road, and they often do. sometimes, they will clear off into the undergrowth never to be seen. 50 50 50, Queue ahead. 40 40 40 Queue ahead. Ten miles later, Road clear- not a queue in sight
50 50 50 Debris in road 40 40 40 Debris in road. Ten miles later, you've guessed it- no debris in road!
It's about time that the authorities could have fines levied against THEM for showing false information time after time.
Have seen such signs very late at night when traffic is light and any supposed queue disappeared hours ago.
Very frustrating to be forced into driving at a ridiculously slow speed for miles when it is blatantly obvious that signage is wrong.
They can't be cleared until Police or HATO do a run through and check its actually gone. If you don't see anything, great! hopefully the animal has gone and they can be cleared shortly.
With debris signs, these are set only when debris has been confirmed, either a operator on CCTV his seen something, or another solid source has, ie a police officer, hato, roadworker has seen the debris. You will only see them in the immediate run up to the debris, usually the 2-3 signals prior to the debris. They will be removed only when the debris has been cleared.
If you are saying you are continually seeing debris signs, and no debris, you're either lying, missing the debris in the road, or are the worlds unluckiest driver.
The queue warning is much of whats been discussed in this thread, the idea is to smooth the throughput of traffic so, in essence you never really 'see' a queue, you just have to slow down a bit so the traffic can clear itself.
Doesn't always work, as highlighted, it can be triggered by a number of things, but in my experience, its a fairly solid system.
Fun fact, we are measured quite heavily against the accuracy and speed signals are cleared and set. So far I think (without checking) each region is hitting their targets.
Hope that helps.
In future, I'm hoping that we can alter the range of signals that can be set, to 'reports of'. that sort of change however, takes significant time.
Edited by Paul 8v on Thursday 30th March 22:19
Paul 8v said:
I get a lower speed can fit more cars on the road but does it have to change at every single gantry?
Not convinced about that eitherIts not about number of cars on the road its about how many cars you can get through a section
If you take cars travelling at 40mph or 80mph for round numbers
take a 1 mile section of road
at 40mph you'll get a certain number of cars through
at 80mph the cars should be twice the distance apart but twice as fast so you'll get the same number through
If however everyone at 80mph chooses to close the gap to the 40mph interval you'll get twice as many cars through
Just for round number sake and you should always leave a safe gap
As per all the comments so far I am also flabbergasted with the way the current "smart networks" are run. I've seen first hand drivers emergency breaking as the speed in the box suddenly becomes 40 from NSL or 60.
Most of the time in particular on the M1 I use it reduces traffic flow. If you think of it from a capacity management perspective you wonder how have they not forecasted the benefits of this in real terms.
Most of the time in particular on the M1 I use it reduces traffic flow. If you think of it from a capacity management perspective you wonder how have they not forecasted the benefits of this in real terms.
fuelracer496 said:
Barriers in particular - they're approved for use based on specific criteria, namely the speed limit
So were they all upgraded when lorry weight limits went from 32 to 38 to 44 tonnes? 'Cos I'm pretty certain a 44 tonne artic is carrying more kinetic energy at 56 mph than a 1.5 tonne car is at 80. I suppose the real problem is you've got minimal strategic infrastructure planning, a small landmass, an ever growing number of drivers and to compound it more people need to use the road network in our evolving decentralised society.
What's the solution?
USA builds ever wider freeways
China builds overhead freeways
Germany and France have higher speed limits
Some, like Columbia, restricts car usage by using 'alternate day' number plates (evens on one day, odds the next)
A few tinker with other alternates like upgrades to public transport
And finally the UK adopts technology to control flow.
What's the solution?
USA builds ever wider freeways
China builds overhead freeways
Germany and France have higher speed limits
Some, like Columbia, restricts car usage by using 'alternate day' number plates (evens on one day, odds the next)
A few tinker with other alternates like upgrades to public transport
And finally the UK adopts technology to control flow.
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