RE: 50 limits by the back door: PH Blog
Discussion
Driving daily on the M6 smart section and many other motorways in general it seems that some of the time the system works, but when the congestion clears or the obstruction is long gone the NSL is not restored and a 40mph sign may be left on a perfectly clear and unobstructed motorway. I guess the people checking the cameras and adjusting signage are more interested in the next round of coffee and doughnuts or Shirleys cake doing the rounds of the nice warm opps room than the drivers and commuters needing to get somewhere. The whole motorway/highways operation could do with an overhaul and take lessons from their counterparts in in Europe with busier roads who have a no nonsense approach.
As a regular M42 user for the last 12 plus years at varying times and days, the system is far from smart.
I won't repeat what others in this thread have said about seemingly arbitrary, infuriating limits. The only saving grace with the M42 is how easy it is to tell which gantries do and don't have cameras and thus which ones are safe to ignore. There does seem to be a common pattern between which ones have cameras and which ones have the arbitrary low limits however...
If a system can be fooled by a single slow moving HGV then in my opinion that is a broken system and not fit for purpose.
I won't repeat what others in this thread have said about seemingly arbitrary, infuriating limits. The only saving grace with the M42 is how easy it is to tell which gantries do and don't have cameras and thus which ones are safe to ignore. There does seem to be a common pattern between which ones have cameras and which ones have the arbitrary low limits however...
If a system can be fooled by a single slow moving HGV then in my opinion that is a broken system and not fit for purpose.
Dan Trent said:
PorkInsider said:
I might be missing something here, but the particular section of the M1 being discussed in the article has some roadside signs - albeit quite small and poorly positioned ones - which read:
REDUCED SPEED LIMIT IN FORCE DURING TECHNOLOGY COMMISIONING
So presumably, even though they've finished the work to get to 4-lane running on that section, they're still fancying around with the CCTV or something?
Or am I missing something else?
Very interesting and your eyesight is clearly better than mine! If that's the case I'll happily eat (some of!) my words! REDUCED SPEED LIMIT IN FORCE DURING TECHNOLOGY COMMISIONING
So presumably, even though they've finished the work to get to 4-lane running on that section, they're still fancying around with the CCTV or something?
Or am I missing something else?
Dan
Said this before on another thread, it's a mindset that has been blamed of another institution, currently in the news, Idea! > Hold a consultation > If it's a Yes, we will say 'on we go', and if it's a No we will say 'we continue’,”
One thing that brasses me off about the 'smart' motorways thing, is that there was an experiment on the M42, hard shoulder running, emergency stopping places every half mile. While this experiment was ongoing, and clearly still had many wrinkles to be sorted, government ministers decided to continue plus with much bigger distances between emergency laybys. Basically they don't give a stuff.
Highways England etc is not fit for purpose, hasn't been for some time. You go abroad and see these wide empty sweeping motorways and grand bridges and structures, going from nowhere to arse end of nowhere else, all built with EU (ie our] money, then you look at our infrastructure, just taking the piss it is.
fuelracer496 said:
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:
I'd rather stick to 70 than go through a decade of roadworks.- 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.
Mandown46 said:
There is a delay, I couldn't tell you for certain what it is, or if it varies between Police force areas.
It was (and I assume still is) 60 seconds. That's if you went under a gantry at 70 just as it became 60. I'm not sure what the score is if it's already 60 and drops to 50.Rich1973 said:
Smart? I think they are bloody stupid. Whoever thought it was a good idea to remove the hard shoulder of a motorway and then call it 'smart' wants their bumps read.
Love to see the risk assessment that says it's a reasonable thing to do.
Dangerous and expensive sticking plaster that doesn't really solve the underlying problem.
100% agree with this...Love to see the risk assessment that says it's a reasonable thing to do.
Dangerous and expensive sticking plaster that doesn't really solve the underlying problem.
It seems to me that a much more cost-effective solution to achieving better traffic flow on motorways (and other multi-lane roads) is to employ more real traffic police and ask them to enforce a keep-left-when-not-overtaking rule.
If they applied the same vigour to that task as they do to tackling driving whilst on a phone/distracted, etc then there would automatically be more road space. Perhaps encouraged by a 6pt £200 FPN for those not doing so!
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...
Mandown46 said:
Sturdy - Its not something I really know much about to give you any technical answers, I'll have a dig about when I'm in next and see what I can find out, but i wouldn't get your hopes up!
Appears there's some news about it at least, looks like it's around the Hindhead Tunnelhttps://www.transport-network.co.uk/Highway-Englan...
Just interested really, as obviously our radar is pretty good and our software handles the TAME equipment, so it could be a fairly cost effective way to implement what they're after.
I suspect we've missed the boat either way, clearly that tender went under our radar (oh that was an inexcusable pun
)Mandown46 said:
Otispunkmeyer said:
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 have a feeling that roundabout is due to be rebuilt (again) with the works about to go on the A453 to the services....I would agree with Dan as well that there is likely an element of lower limits by stealth/back door. Purely because they've been doing it anyway with more minor roads. In fact in those cases, they don't even ask; one day a NSL goes to a 50, then a 40. Then your village becomes 20. Just overnight. No questions asked.
Attilauk said:
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...
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...
Unfortunately that's not the way safety worksThey 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...
For some reason people are a lot more wary at 70 than 50 and that runs throughout the scale
So if the limits are being placed for the reason youve said it may well be counter productive, and which could explain why when in places they do cone off a lane without imposing a limit things still seem to run ok.
So if its not there for reason (1) safety of workforce or (2) safety of road users, why else would they introduce these limits and cameras
kwit gesticulating madly at me yesterday in my rearview given that I slowed to 40 as the gantry limit which I know is monitored by hadecs. I wound my window down and pointed the camera's out to him but he still looked dazed and confused 
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 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.
Mandown46 said:
Debaser said:
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?)
There is a delay, I couldn't tell you for certain what it is, or if it varies between Police force areas.
TX.
saaby93 said:
Unfortunately that's not the way safety works
For some reason people are a lot more wary at 70 than 50 and that runs throughout the scale
So if the limits are being placed for the reason youve said it may well be counter productive, and which could explain why when in places they do cone off a lane without imposing a limit things still seem to run ok.
So if its not there for reason (1) safety of workforce or (2) safety of road users, why else would they introduce these limits and cameras
Care to back that conjecture up with a peer reviewed study?For some reason people are a lot more wary at 70 than 50 and that runs throughout the scale
So if the limits are being placed for the reason youve said it may well be counter productive, and which could explain why when in places they do cone off a lane without imposing a limit things still seem to run ok.
So if its not there for reason (1) safety of workforce or (2) safety of road users, why else would they introduce these limits and cameras
Whether people are 'more wary' at 70 or not isn't the point, in narrow lanes the vehicles are closer together so it is safer for them to be going slower in case someone does something unexpected.
It all comes down to traffic volumes, if the volume is low enough for the road to not go over capacity then we can shut a lane without causing too much of an issue, this would always be a preferred option for the works as it gives us much more working room. If the volume is too high to do away with a lane and we need additional working room then narrow lanes is our normal traffic management route. If we are working in narrow lanes then you can therefore automatically assume that there is increased traffic volume at certain times of the day, except this traffic volume is now much closer together (minimum acceptable lane width in lane 2&3 is only 2.5m) and you want this traffic to continue at 70+? Maybe it would help if you could see the carnage that passes for driving from a roadworkers perspective?
I have certainly witnessed that in roadworks with a reduced limit but no cameras, nobody sticks to the reduced limit. Hence the cameras...
Terminator X said:
is related to emissions
It's interesting looking at the estimated emissions compared to vehicle type / speed / flow.The real key to emissions is to keep vehicles moving, as once HGVs and cars are crawling along or stationary, the emissions climb significantly.
The 2 lane road outside our office queues very reliably in rush hour, and the (estimated) CO2 / NOx emissions for one lane of very slow moving traffic can easily match a single carriageway of the M25 when it's flowing freely, even though the M25 has 10 times as many vehicles...
The estimated emissions are done from Highways England's own estimation routines, so they should be fairly representative.
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