[Closed] 60mph limit of the M1

And the lower speed limit should cut congestion.

Why?

and save a chuck of fuel too I imagine

rush hour speed limits are a joke anyway really

I was about to say you'd be lucky to average 60 anyway usually on much of the M1.

will it change anything other than the signs?

[i]Why? [/i]

you get a lot less of that 'mexican wave' type of traffic where people accelerate towards slower moving cars and then over brake and a mile behind them the traffic all grinds to a halt 20 minutes later.

And the lower speed limit should cut congestion.
Why?

It's very widely known and studied that lower maximum speeds result in smoother traffic and higher actual speed overall.

Why not just have a variable speed limit?

Can't see the justification for making the speed limit 60mph at 7am on a Sunday morning

[i]Why not just have a variable speed limit?[/i]

Infrastructure costs, I'd imagine. Plus disruption installing it all.

Makes so little difference to journey times, and saves a bunch of fuel. Why not?

The M6 has a managed/mandatory speed limit of 50mph from J10 to J13 and beyond.

During peak times it makes little difference to journey times because everyone is nose-to-tail anyway in a 51 mph freight train. what was the hard shoulder is simply another lane of lorries engaged in 10-mile overtakes it makes no difference to congestion

Outside peak times the mandatory 50 mph limit is both frustrating and rewarding. Frustrating because 50 mph on a fairly empty motorway feels as though you are barely moving and for short journeys the motorway is no quicker than going on the adjacent A-roads. Rewarding because you can sit with the cruise control at 51 mph and watch the mpg go to 99.9 mpg

Plus disruption installing it all.

They could do it now whilst there's a 50mph limit as they're changing all the central reservation.

wwaswas - Member

you get a lot less of that 'mexican wave' type of traffic where people accelerate towards slower moving cars and then over brake and a mile behind them the traffic all grinds to a halt 20 minutes later.

Why would a lower limit prompt a reduction in this behaviour?
An evidence for this?

Not trolling, just that speed limit v average speed isn't something I've looked into before.

I'm for it, I don't use the M1 😆

Infrastructure costs, I'd imagine. Plus disruption installing it all.

Motorways have signs in place already for adjusting speeds and other warnings on the fly.

Variable speed limits.. dear me.. a great idea ruined by mass stupidity 🙁

They spent ages putting one in around Newport, where congestion is bad, and everyone ignores it. We're apparently too dim to realise why it's there. People seem to stick to it on the M25 though.

Frustrating because 50 mph on a fairly empty motorway feels as though you are barely moving

The point about it being variable is that they switch it off when the motorway is fairly empty. Or they should, at least.

Both the Newport and Bristol sections on the M4 took years to install. I guess because the old signs didn't support colour, so they couldn't show the legally required red and white.

[i]Motorways have signs in place already for adjusting speeds and other warnings on the fly. [/i]

having seen what they did on the M25 for variable speed limits it's a lot more than just using the 'fog' signs during the rush hour to control speeds, though?

[i]Why would a lower limit prompt a reduction in this behaviour?[/i]

because the difference in speed between slow and fast traffic is reduced. I don't have specific documents but a quick google will show you empirical evidence that reducing maximum speed increases traffic flow beyond a certain vehicles/hour throughput on a give road.

Variable speed limits.. dear me.. a great idea ruined by mass stupidity

The areas I've travelled on where they're used seem fairly successful, M42 going into Birmingham and bottom of the M1

Infrastructure costs, I'd imagine. Plus disruption installing it all.
Motorways have signs in place already for adjusting speeds and other warnings on the fly.

wwaswas - Member

Why would a lower limit prompt a reduction in this behaviour?

because the difference in speed between slow and fast traffic is reduced. I don't have specific documents but a quick google will show you empirical evidence that reducing maximum speed increases traffic flow beyond a certain vehicles/hour throughput on a give road.

Ta.
I'll have a good look later.

I remember Newport when it was 70mph...I used to crawl through there at 10mph most mornings...now it's 50mph most of the time, and everything flies through at 50mph. It's way betterer than it used to be.

Problem at newport used to be high volumes joining motorway at slow speed...as wwaswas describes...the differential has been reduced now and everthing slips through better - still a lot of traffc but its usually moving well

I don't think the variable signs at Newport are enforced yet though..plenty seem to go through at 70

Motorways have signs in place already for adjusting speeds and other warnings on the fly.

Mind you they also sometimes can't be trusted, I've turned off a motorway warning of multiple lane closures and seen from the slip road a free flowing fully open motorway and run into a massive tailback caused by everyone else exiting the motorway.

Variable speed limits should be more widespread I reckon, evidence does seem to be that they shift a lot of traffic, driver perception is really not reliable.

Is there any research on banning lane changing too? Ie preventing lane hopping, reckon stopping that could improve throughput too

According to that article it's a distance of 32 miles. SO by reducing the speed limit, assuming you covered that distance at the speed limit, the journey time will increase by about 4 and a half minutes. What a hardship

[img] [/img]

that's BS. The thing that causes conjestion on motorways - the sort of conjestion where you are sat in a jam or slow moving traffic, for no apparent reason whatsoever, is peoples behaviours - primarily they travel too close to the car in front. This means they over-react to speed changes, hit their brakes too hard, causing the person to hit their brakes too hard, then accellarate away, which sets up a caterpillar motion of people braking harder and harder as you travel up the traffic flow until such time they brake to a halt.

If people could drive sensibly, leave a sensible amount of space between the car in front, then speed is not an issue and traffic flow would be nice and smooth and even.

Lowering the speed limit reduces this caterpillar effect, but doesn't stop it and is treating the symptom and not the cause. Granted, the cause is something that is difficult to police and tackle.

Of course it doesn't help that you have vehicles with different speed limits using the motorway - lorries limited to 56mph, towing vehicles limited to 60mph and normal cars traveling at a wide range of speeds. This just causes people to have to frequently adjust their speeds which just sets up the caterpillar effect.

wobbliscott - Member

Lowering the speed limit ... is treating the symptom and not the cause.

isn't the idea (in this case) to reduce air pollution?

Wobbliscot setting everyone at the same speed that everyone can achieve, ie 50 should help a lot, and of course at a slower uniform speed people can safely travel closer together and [i]should[/i] be less fannying around.

Awhiles away with your hippy shit, no one cares, tell drivers traffic will be improved and you may get some support 🙂

[quote=rocketman said]Rewarding because you can sit with the cruise control at 51 mph and watch the mpg go to 99.9 mpg

Check your speedo accuracy with a GPS and you'll probably find that 50mph actual is around 55mph indicated on your dash. So a cruise setting of ~56mph is probably still fine.

* probably! Most speedos over read by 10%

THere will be disruption because they are bound to want to install the money making machines to maximise the revenue making opportunities that reducung speed limits provides.

People are pillocks and don't see there behaviour as having an affect on the rest of the traffic system and will continue to drive like tits because of their own self importance. I leave a gap of three car lengths in slow moving traffic so I can use my accelerator and clutch to control speed, only touching the breaks when deeming it necessary to stop, not slow down. I get twunts coming from behind me, under and overtaking and shooting round then into the space I've left and slam on. COCKS!

chrismac - Member
THere will be disruption because they are bound to want to install the money making machines to maximise the revenue making opportunities that reducung speed limits provides.

You forgot to mention the "War on Motorists!"

I wonder how much pollution will be cut by, and who will benefit from this reduced pollution. Is it surrounding built-up areas? Is there a weather system there that doesn't remove pollution very well?

If people could drive sensibly, leave a sensible amount of space between the car in front, then speed is not an issue and traffic flow would be nice and smooth and even.

Agree to a certain extent - however it only reduces and will never remove the caterpillar effect. Even if traffic speed is slower and gaps are bigger, when a car in front slows - whether by braking or just lifting off the gas - the car behind takes a bit of time to register that this has happened. If they then apply the same amount of slowing, down to the same speed, the effect of the thinking delay is to close the gap on the car in front; so they need to actually slow down more in order to maintain the same gap, then speed up to maintain it. The car behind this one has the same effect except the slowing force is higher again. Multiply by dozens of repeats when traffic is essentially at the road capacity, and the cars at the back have to slow down to almost stop before starting again.

The trouble is twofold in my opinion - firstly, cars that see that it says 50 but insist on tailgating as if getting past makes any real difference. They make the gaps smaller, to the extreme case where thinking time is almost as much as the gap itself, and then need to jam on brakes to avoid a rear ender, means the number of cars to create a caterpillar effect is smaller. And more important, twunts who insist on driving in the outside lane nose to tail when there are two other (relatively) empty lanes that could be used so the outside lane isn't rammed solid.

The biggest issue I reckon is that SOME people slow to 50mph but some insist on bombing through anyway, which causes no end of mayhem.

THere will be disruption because they are bound to want to install the money making machines to maximise the revenue making opportunities that reducung speed limits provides.

Can someone tell me why the police making money is a bad thing?

who will benefit from this reduced pollution.

Good question. This is all well and good for people who breathe air and live somewhere within the earth's atmosphere, but what is it going to do for [i]me[/i]?

wwaswas - Member
you get a lot less of that 'mexican wave' type of traffic where people accelerate towards slower moving cars and then over brake and a mile behind them the traffic all grinds to a halt 20 minutes later.

Why would a lower limit prompt a reduction in this behaviour?
An evidence for this?

Not trolling, just that speed limit v average speed isn't something I've looked into before.

The best evidence would probably come from the M25 which is where I think this was first implemented. Its not just setting a limit but enforcing it rigourously. Bringing the speed down to the slowest road users - trucks basically - stops people switching lanes to pass slower traffic. Otherwise when the roads are busy people move lanes into smaller spaces, the car behind them dabs the brakes, the car behind them brakes harder - people see lights ahead so they all brake and the everyone just stops. Then pull away again into what is now an empty road - but now the traffic is even denser and expectant of another sudden halt again so even more likely to dab the brakes and it happens again. The lower speed limits have to be harshly policed as one or two drivers flouting there limit buggers it all up so they have to be pretty draconian.

The difficulty with any data derived though is while the experiments like the M25 have been running the traffic load has been increasing so an alleviation of congestion is being offset by more vehicles now being on the road.

I think it's been known for about 40 years that you can't alleviate congestion by building more roads...it doesn't stop politicians from trying though.

I expect it was Cat Deeley who said Insanity is when you keep repeating the same experiment expecting different results...or something.

THere will be disruption because they are bound to want to install the money making machines to maximise the revenue making opportunities that reducung speed limits provides.

This has recently been implemented in the M62 Near Leeds/Bradford. It is a variable speed limit with Gatso cameras. It works brilliantly and has made a huge difference.

The key difference is the rigourous enforcement mentioned above.

I use the M25 quite a lot, well at least once every couple of weeks. Last night at around 11pm the signs were flashing 60 because of the rain/wind combo and I was in the slow lane (typical driving habit for me I'm afraid) to which near the exit for the A217 a Passat hacked on by with it's drivers side tyre blown out and rubber flying everywhere.. so I caught up with him in the 50mph limit near Clackett in the roadworks and the blender was still driving along on the rim...at 50mph... I pulled back sharpish and we entertained ourselves watching from behind as the car swerved this way and that..

It was awful driving rain, so I understand why whoever it was didn't want to get out and change it.. 😯

[quote=BoardinBob]Meanwhile in Africa

A fine piece of whataboutery.

I've always found the variable limits on the M25 to work well - but the ones on the M42 are often daft (suggesting a lowered speed when there's not actually that much traffic, and actually creating congestion). It may be a difference in the times I use each one, but I think it's a difference in implementation.

The difficulty with any data derived though is while the experiments like the M25 have been running the traffic load has been increasing so an alleviation of congestion is being offset by more vehicles now being on the road.

These schemes aren't really aimed at reducing congestion though. The aim is to increase the capacity of the road in terms of cars per hour, and this certainly gets measured. And it works, hence the fact that managed motorways are being rolled out in lots of other places.

I've always found the variable limits on the M25 to work well - but the ones on the M42 are often daft ([b]suggesting a lowered speed when there's not actually that much traffic, and actually creating congestion[/b]). It may be a difference in the times I use each one, but I think it's a difference in implementation

But if they're changing the limit a couple of miles before the congestion then it would look like that, wouldn't it?

I've always found the variable limits on the M25 to work well - but the ones on the M42 are often daft (suggesting a lowered speed when there's not actually that much traffic, and actually creating congestion). It may be a difference in the times I use each one, but I think it's a difference in implementation.

It could be that even with the new signs the motorway is still over it's (now higher) capacity but only in specific zones. So they manage the traffic as much as they can until a queue inevitably forms.

The speed is reduced when the traffic is seeminly clear as the traffic manager can see that the sum of the cars coming down the motorway, plus the cars joining at upcoming junctions is higher than the capacity of the road. So they slow down the cars approaching and reduce the number cars joining using the slip road lights in attempt to stop the number of cars on the road road exceeding its maxium flow rate (cars per hour). However if there are still too many cars after they have used all their tools then a queue will still form.

To the observer in a car approaching the congestion zone all they see is speed limits and then a queue and spot the correlation between speed limits and queues and jumped to conclusions, but what they have failed to realised is that the queue and the speed limit had the same root cause, the predicted volume of traffic, the speed limit will have actually reduced the severity of the queue but this is not apparent.

Is there any research on banning lane changing too? Ie preventing lane hopping, reckon stopping that could improve throughput too

I believe it has a similar effect.

IIRC any kind of "disruption" to "perfect traffic flow" will introduce one of these caterpillar wave thingummies. Disruptions include anything - lane changing, unnecessary speedup/slowdown, junctions, lanes merging, etc...

suggesting a lowered speed when there's not actually that much traffic, and actually creating congestion

I think you've just neatly made the point about drivers not being able to be aware of the whole road network and how they thusly can't anticipate the required speed limits for maximum traffic flow. We can't seeing the wood for the trees, etc.

Is the M1 really near Matlock? I never knew that!

Is the M1 really near Matlock? I never knew that

If you count 10 miles as near then yes

Thing is, without any viable and practical alternative to travel by private motor vehicle, all these schemes do is move the congestion somewhere else. So yes, they will almost certainly claim that the scheme "reduced pollution" or whatever, but in fact, next year, there will still be more cars in the road and more congestion............

Thing is, without any viable and practical alternative to travel by private motor vehicle, all these schemes do is move the congestion somewhere else. So yes, they will almost certainly claim that the scheme "reduced pollution" or whatever, but in fact, next year, there will still be more cars in the road and more congestion............

Plenty of alternatives, just whether you think they are viable and that isn't the same as being viable.

And if you want to get rid of congestion there is only one solution, make driving a pain in the arse that no one in their right mind would do.

make driving a pain in the arse that no one in their right mind would do.

that's a rather negative view point. The better solution is to have more viable alternatives so that using the car isn't the obvious choice for most.

Of course, that probably requires investment in most cases but if we spent money on that rather than more roads...

As has been posted before speed cameras will be installed which will catch unawares motorists and MAKE MONEY.

The correct solution is to install variable speed limits at peak hours.

We all need to be very aware that "environmental concerns" is the new political catch all to justify things which have no relation to protecting the environment.

This isn't just related to the UK, the same is being done elsewhere, the speed limit on the Paris Peripherique is being cut from 80 to 70kmph for "environmental reasons"

[i]The correct solution is to install variable speed limits at peak hours.[/i]

enforced by speed cameras?

As has been posted before speed cameras will be installed which will catch unawares motorists and MAKE MONEY.

How can you be unaware?

Or do you have information that the speed limit signs will have a big quesion mark and it'll be like a lottery so you have to guess the limit and you get a fine if you guess wrong and go too fast?

If it'd get everyone driving at consistent speed and stop the cascade traffic jams then I'd be all for average speed cameras and variable speed limits along every major road.

my office window looks out onto the M1 - half a mile south of J33.

it's 4.47pm, and already traffic is proceeding such that a 60mph limit would inconvenience no-one at all.

question: is it the heavy traffic, or the fast traffic that's causing the air pollution?

(they seem to be approximately mutually exclusive)

As has been posted before speed cameras will be installed which will catch unawares motorists and MAKE MONEY.

Again - why is this a bad thing?

BECAUSE OF THE WAR ON MOTORISTS!!!!!!!!!!!!!!!!!!!!!!!

question: is it the heavy traffic, or the fast traffic that's causing the air pollution?

Both, but only the fast traffic's pollution will be reduced by this measure.

If it'd get everyone driving at consistent speed and stop the cascade traffic jams then I'd be all for average speed cameras and variable speed limits along every major road.

This is the only way. The issue with the current speed camera's is that they encourage people to brake heavily, then speed up. Bad for congestion and pollution.

But people are incredibly resistant to them as very few people want to drive at 60/70 when the roads are empty. I'd agree with this, trolling along that slowly on an empty road is infuriating.

It seems a fairly open secret that the speed camera's on the M1 between 25 and 28 are only active when then variable speed limit is enforce. I don't know why this couldn't be publicised and average speed camera's used to control speed only when the temp speed limits are in force. The aim of this being to reduce congestion, not dangerious driving.

The police can then target dangerous driving when the camera's are off if they want with other more effective methods than static speed camera's

I wonder what the effect would be of reprogramming all traffic lights in the UK to go on 'flashing amber' (proceed with caution) when not in rush hour could have on pollution rather than focus on one 32 mile stretch of one motorway?

I am sick of stopping at red lights at 2am whilst the set goes through its sequence. They do this in other parts of the world I believe?

Just a thought.

I hope these jeb ends don't get this through! Either it's so busy you can't get up to 60 or it's clear and then you'll be stuck doing 60!

As for reducing pollution if this does come into effect I'm going to drive through in 3rd gear increasing the amount of pollution my car gives out! Seen as I have a company car and pay per mile and not fuel used it won't cost me any extra to teach them a lesson!

Teach them a lesson? Wtf are you talking about? Have a word with yourself.

Do I need to draw you a diagram sweetheart?

Their doing it to cut pollution apparently! So I'll lay the smack down on them by busting out more pollution doing 60 in 3rd gear than 70 in 5th! Simples!

Stick it to The Man!

Meanwhile, on my 5min 37sec walking commute, I saw a Robin.

Their doing it to cut pollution apparently! So I'll lay the smack down on them by busting out more pollution doing 60 in 3rd gear than 70 in 5th! Simples!

You're being ironic, I assume...

I think he's just a moron...

I'm not sure about anyone else but I'm so turned on by enduroganster right now, I wonder if he'd let me have sex with him?

I'm available if endurogangster isn't feeling the love. 🙂 ❓

Say something ****ish and I'll see if I can get another semi on.

I can do 60 in second in my car. ❓

The planned Manchester M60 Managed Motorway scheme has been binned on health grounds. A report has suggested it will lead negative impact on air quality.

[url= http://www.transport-network.co.uk/Highways-Agency-scraps-M60-smart-motorway-plan-on-health-grounds/9745#. ]Highways Agency scrap M60 managed motorway[/url]

OMG - this takes me back to Littles Law and M/M/1 models 😆

Variable speed limits on M1 between J24 and J28. I travel north from J25 to J27 when driving to work and most mornings the southbound traffic is congested. But the signs are lit and woe betide speeders as I have seen the GATSOs flash many-a-time.#

Personally I'm looking forward to self-driving cars. Congestion would reduce drastically, fewer accidents and I can relax going to and from my MTB meets. 😀

It works on the M25 and M42 so why not?

A word to the wise. The new cameras on the M62 are set really low. Below 80 I've been told by my brother-in-law who works for HA. Don't give the ba@ta*ds anymore money!

Basically the HA have committed £100+ million to the ALR scheme between J28 and J35. The pollution problem has been holding up the scheme at great cost to themselves. This mandatory 60 from 7-7 will mean they can go ahead with the scheme as they can bring the final pollution level down to an acceptable level.

who will benefit from this reduced pollution?

Good question. This is all well and good for people who breathe air and live somewhere within the earth's atmosphere, but what is it going to do for me?

it was a genuine question. why do it locally and not across the road network? is there a particular problem in that area due to the concentration of roads/ people?

I travel J36/J35a to J33 every weekday, the central barrier replacement roadworks have now gone but there was no notable effect on my journey time when they and the accompanying 50mph limit was in place. I'm sure having all 3 lanes live across Tinsley viaduct would help with average speed/traffic volumes/pollution levels but it would seem that particular structure was so badly designed it simply can't be fixed.

As has been posted before speed cameras will be installed which will catch unawares motorists and MAKE MONEY.

[quote=mrmonkfinger]

suggesting a lowered speed when there's not actually that much traffic, and actually creating congestion

Except when I drive on the M42 I always drive end to end of the managed section and the majority of the time end to end of the M42, and the occasions I'm complaining about there isn't any downstream queuing or any signs of conditions which might result in it. I'm fairly confident I'm not missing anything and that higher speeds wouldn't result in congestion - I've got quite a bit of experience of driving on motorways at various states of congestion, an it is possible to be aware of what causes it. Remember I'm comparing with my experience of driving through the similar section on the M25, where at similar traffic levels the speed limits aren't lowered.

I agree that managed speed limits on motorways can work well - the section on the M6 I use fairly frequently also works well, it just seems to be the M42 where the algorithms used are screwed.

I'm not sure about anyone else but I'm so turned on by enduroganster right now, I wonder if he'd let me have sex with him?

You don't have sex with endurogangster! You strap yourself in and experience the G's!

Lower speed will mean less noise.
I saw a programme about the noise levels on the A4 which are horrendous. That's why it's 40 mph.
They were talking to an old guy who said the noise was intolerable. I immediately thought "why did you move there?"
They then showed a picture of the road when he moved in. It looked like a country lane.
So peoples cut your speed and give the poor sods who live near these roads a better standard of life.

that's a rather negative view point. The better solution is to have more viable alternatives so that using the car isn't the obvious choice for most.

Don't give the ba@ta*ds anymore money!

They aren't bastards, they're the police, and they look after us. You'd be the first person moaning about police funding if they didn't have enough resources to find the person who stole your bike, for example.