http://www.bbc.co.uk/news/uk-england-south-yorkshire-18261619

Can't see that being too popular

One of the main causes of pollution within Sheffield is the constant stopping and starting of traffic caused by idiotically programmed traffic signals.

It does not need a brain of Britain to program these traffic signals. It is just unfortunate that the traffic management in Sheffield seem to have employed bird brains to program the traffic signals instead.

Yesterday, negotiating the (South) Tinsley roundabout under the M1, I had to pull up at every set of traffic lights. This was not due to any traffic but due to the pathetic phasing of the traffic signals. I was stopped firstly at the signals at the end of the Viaduct, then the lights for Sheffield Road (A6178 towards Rotherham), then the lights for Bawtry Road (A631), then the lights for the M1 south, then the lights for Shepcote Lane (A631) and finally the lights for Sheffield Road (A6178 towards Meadowhall and Sheffield). That is SIX times the lights were at red. Now, I was on my cycle so apart from some perspiration and exhaled carbon dioxide from breathing, very little pollution but what about cars, taxies, lorries and busses having to stop and start each time? THAT is the reason for all the pollution at Tinsley.

Sorting out the traffic light phasing would be a better option for sorting out the pollution than any 50 mph limit on the M1.

Yet more evidence of Sheffield Council's desire to slow everyone down to a crawl no matter what sort of road they're on. They can't really use the safety angle this time so they're going for air quality instead. I wonder how much evidence there is that making people go at 50mph actually reduces the total emissions - after all at a slower speed cars will spend more time on that particular stretch of road so the air quality may actually get worse.

It does not need a brain of Britain to program these traffic signals. It is just unfortunate that the traffic management in Sheffield seem to have employed bird brains to program the traffic signals instead.
That's a bit unfair on birds - they clearly understand traffic lights as well as any traffic planner round here...

http://www.youtube.com/watch?v=BGPGknpq3e0

So in a time where 80mph is being considered for the whole motorway network, SCC want to reduce it by 20mph?

Idiocy at it's finest. There's no wonder people avoid Sheffield with the intellect of SCC

So in a time where 80mph is being considered for the whole motorway network, SCC want to reduce it by 20mph?

Idiocy at it's finest. There's no wonder people avoid Sheffield with the intellect of SCC

That's true, driving through Sheffield is such a ball ache but perhaps slowing the traffic down forces people to look at the place rather than drive by without noticing it, clever ploy.

Imagine how much revenue they will rake in from speed cameras.

So in a time where 80mph is being considered for the whole motorway network, SCC want to reduce it by 20mph?

Idiocy at it's finest. There's no wonder people avoid Sheffield with the intellect of SCC

How do you suggest that they tackle the air pollution problem?

How do you suggest that they tackle the air pollution problem?

See post #2 ..may be some mileage in that..

One of the main causes of pollution within Sheffield is the constant stopping and starting of traffic caused by idiotically programmed traffic signals.

It does not need a brain of Britain to program these traffic signals. It is just unfortunate that the traffic management in Sheffield seem to have employed bird brains to program the traffic signals instead.

Yesterday, negotiating the (South) Tinsley roundabout under the M1, I had to pull up at every set of traffic lights. This was not due to any traffic but due to the pathetic phasing of the traffic signals. I was stopped firstly at the signals at the end of the Viaduct, then the lights for Sheffield Road (A6178 towards Rotherham), then the lights for Bawtry Road (A631), then the lights for the M1 south, then the lights for Shepcote Lane (A631) and finally the lights for Sheffield Road (A6178 towards Meadowhall and Sheffield). That is SIX times the lights were at red. Now, I was on my cycle so apart from some perspiration and exhaled carbon dioxide from breathing, very little pollution but what about cars, taxies, lorries and busses having to stop and start each time? THAT is the reason for all the pollution at Tinsley.

Sorting out the traffic light phasing would be a better option for sorting out the pollution than any 50 mph limit on the M1.

Totally agree with you about traffic light phasing. I regularly drive through Sheffield at ungodly hours, it is amazing how many lights you get stopped at when there is no other traffic on the road. I can only conclude it is deliberate. Worst example for me is if you drive from the Leadmill area on Sheaf Street to Park Square roundabout. You will generally get stopped at Harmer Lane (where busses turn off to go up to the bus station - bear in mind this is early hours of the morning we're talking about ) - then you will get stopped at the next set of lights (Pond St) before finally getting stopped again at Park Square. Stopped three times for absolutely no reason. I have also noticed Tinsley to be bad, especially Shepcote Lane/Europa Link Road area. Total waste of time and fuel. It simply has to be deliberate, nobody could be so stupid as to phase lights like that by accident.

Funnily enough I also do a lot of night time driving in Leeds (as I work there) and there is no problem there, come off the motorway and you're on a green light wave all the way into the city centre. Same leaving, once you're on the main road to the M621 you're on greens all the way. Why can't we do the same here?

they wont, as long as the car drivers keep contributing to the nations coffers, then the goverment does not give a stuff about the health problems. look at london, and why didnt they let segways on the road??. electric and very practical for short journeys, they would have cut traffic in cities massively

Imagine how much revenue they will rake in from speed cameras.

None, as far as law-abiding folk are concerned.

How much money they rake in from law-breakers is of no concern to anyone.

Often wondered if our traffic lights are twined. I remember in a thread about woodseats, Planner1 (sorry if it wasn’t you) defended the amount of time pedestrians had to wait for the crossing to turn red to allow them to cross saying all the traffic lights in woodseats are twinned to aid the flow of road traffic through the area.

However, if this is the case, why does it not happen with the lights near the Uni tram stop? On the way from Brookhill down to St Mary’s there are 3 sets of lights within about 100m, all going to red at different times, meaning you get stuck in between them.

I doesnt happen like that in the movies (ie the Italian Job!)

How do you suggest that they tackle the air pollution problem?

I agree that they should definitely be looking at traffic light timings before anything else. There are far too many instances around the city of cars being held at traffic lights puffing out smoke while a green light adorns an empty road. However, this would be a huge job which would require thinking and figures and communicating and work which SCC don't seem too fond of. It's much easier to just buy a shed load of 50mph signs and stick them on the road as they did with the A61.

However, if this is the case, why does it not happen with the lights near the Uni tram stop? On the way from Brookhill down to St Mary’s there are 3 sets of lights within about 100m, all going to red at different times, meaning you get stuck in between them.

Penistone Road beats that hands down. At any one time you can see about 10 sets of traffic lights ahead of you. Terrible, terrible town planning.

Often wondered if our traffic lights are twined. I remember in a thread about woodseats, Planner1 (sorry if it wasn’t you) defended the amount of time pedestrians had to wait for the crossing to turn red to allow them to cross saying all the traffic lights in woodseats are twinned to aid the flow of road traffic through the area.

However, if this is the case, why does it not happen with the lights near the Uni tram stop? On the way from Brookhill down to St Mary’s there are 3 sets of lights within about 100m, all going to red at different times, meaning you get stuck in between them.

I doesnt happen like that in the movies (ie the Italian Job!)

The Woodseats scheme was a total shambles, I am amazed anybody would even try defend it and the ridiculous amount of public money which was squandered

Penistone Road beats that hands down. At any one time you can see about 10 sets of traffic lights ahead of you. Terrible, terrible town planning.

ride a bicycle and ignore them all, you would be amazed at the time thats saved doing that

Penistone Road beats that hands down. At any one time you can see about 10 sets of traffic lights ahead of you. Terrible, terrible town planning.

Another bad one is Derek Dooley Way (no not the stupid name,) get stopped at Nursery Street and you will also be stopping at Saville Street and finally the Wicker. And this is supposed to be a main trunk road!

How do you suggest that they tackle the air pollution problem?

There is no air polution problem,it is an excuse to tax us more :roll:

How do you suggest that they tackle the air pollution problem?

By not making drivers who have no choice to be on the roads stop at every set of lights possible thus braking, then idling and finally accelerating back up to speed only to be stopped again. That would be a great start.

Penistone Road beats that hands down. At any one time you can see about 10 sets of traffic lights ahead of you. Terrible, terrible town planning.

how do you think i get on to Brookhill ;)

Yep, i once worked out the mean distacne between lights, something like 200m for 1.5 mils.

None, as far as law-abiding folk are concerned.

How much money they rake in from law-breakers is of no concern to anyone.

Could you provide a list of things people are allowed to be concerned about, please.

Penistone Road beats that hands down. At any one time you can see about 10 sets of traffic lights ahead of you. Terrible, terrible town planning.

There is a way to beat them.When one goes green, put your foot down and as you approach the next set,they will turn to amber and as it isnt safe to break at speed,suddenly,Keep your foot down and you can just get through all sets on green.:thumbsup:

There is no air polution problem,it is an excuse to tax us more :roll:

There is no excuse for ignorance in the digital age. You might want to check your claim out in a bit more detail.

Unless you are simply trolling, of course.

By not making drivers who have no choice to be on the roads stop at every set of lights possible thus braking, then idling and finally accelerating back up to speed only to be stopped again. That would be a great start.

I agree.

I'm not sure what I think about lowering the speed limit. It will help to reduce emissions and it shouldn't significantly affect journey times.

What we really need is an intelligent traffic management system, like the ones around Birmingham and Nottingham.

Could you provide a list of things people are allowed to be concerned about, please.

People are allowed to be concerned about anything they choose. What they have reason to be concerned about is quite another matter; and from personal experience, I have never met, or even heard of, anybody who thinks that fining people who break the law is any kind of a problem, or that anyone who is so fined can ever have anyone other than themselves to blame.

Correct Sibon and yet in the Ivory Tower they choose to focus on Motorway Speed limits. On the one hand we have had the Government recently consulting on raising the speed to 80mph yet here in the Republic of South Yorkshire we choose to go the other way. It is a shame there isn't a facepalm smiley on here :)

Correct Sibon and yet in the Ivory Tower they choose to focus on Motorway Speed limits. On the one hand we have had the Government recently consulting on raising the speed to 80mph yet here in the Republic of South Yorkshire we choose to go the other way. It is a shame there isn't a facepalm smiley on here :)

Thread here http://www.sheffieldforum.co.uk/showthread.php?t=996338 :)

Between Wadsley Bridge and Shalesmoor roundabout there are 32 sets of traffic lights. How can this be conducive to traffic flow and polution reduction.

Correct Sibon and yet in the Ivory Tower they choose to focus on Motorway Speed limits. On the one hand we have had the Government recently consulting on raising the speed to 80mph yet here in the Republic of South Yorkshire we choose to go the other way. It is a shame there isn't a facepalm smiley on here :)

There are times of the day when it would be eminently sensible to have a 50 limit. And times when we could safely have an 80 limit without causing any danger or pollution problems.

One of the problems with the country is that we are very binary in our approach to problems.

There are times of the day when it would be eminently sensible to have a 50 limit. And times when we could safely have an 80 limit without causing any danger or pollution problems.

One of the problems with the country is that we are very binary in our approach to problems.

I hear that the variable speed limit signs on the M25 work well, they should maybe think about that up here instead of a blanket lowering of the speed limit, although variable speed limits are to smooth the flow of traffic as opposed to slow it down so maybe that misses the point somewhat.

Thread here http://www.sheffieldforum.co.uk/showthread.php?t=996338 :)

:thumbsup:

How do you suggest that they tackle the air pollution problem?

Your not really daft enough to think that is the genuine reason are you?

Your not really daft enough to think that is the genuine reason are you?

It is clearly the reason. Our air quality is very poor. There is a clear link between level of traffic/ speed of traffic and levels of various air pollutants.

Before you make yourself look "daft" you might like to stop and think:wink:

They are "considering" a "bid", there's a long way to go before its implemented, if at all.

They have no juristiction over the M1, all they can do is put their case forward but even SCC getting that far is not certain.

There is no air polution problem,it is an excuse to tax us more :roll:

Presumably you can provide figures to back this claim.

The monitoring stations at Tinsley have often shown concentrations of NOx double that considered safe.

It is true that these levels went down while the 50mph limit was enforced when the viaduct was being repaired.

I don't have access to figures that say if this was directly as a result of the speed or if less traffic used the viaduct.

Look North covered it twice recently

http://www.youtube.com/watch?v=I0hLFAu4eAM

and

http://www.youtube.com/watch?v=8OejMNrvo6o

People are allowed to be concerned about anything they choose. What they have reason to be concerned about is quite another matter; and from personal experience, I have never met, or even heard of, anybody who thinks that fining people who break the law is any kind of a problem, or that anyone who is so fined can ever have anyone other than themselves to blame.


What a crock!!

Anybody who has any common sense knows that thousands of speed limits have been reduced without good reason over the last 10 years or so and it has nothing to do with road safety at all infact lowering the limits adds to the problems not cures them.
You only need to look at Swindon who went against the grain and turned off all their speed cameras and as a result now officially have the safest roads in the UK.
The more speed limits are reduced in inapropriate places the more they will be ignored and so they should be its not about safety,emmisions or any other of the rubbish thats spouted the end game is pay per mile but that will only be accepted if theres enough conjestion,first we need to design it and 50 on the M1 is just another bottleneck of thousands already in place.

Im sure your aware really even if you sound like you dont ,but stopping and starting,lowering and increasing speed ADDS to emissions (less MPG) than a steady 70 mph ever would.To minimise emmisions then common sense would be to make the roads with LESS bottle necks not MORE but then there aint much common sense round here is there?

It is clearly the reason. Our air quality is very poor. There is a clear link between level of traffic/ speed of traffic and levels of various air pollutants.

Before you make yourself look "daft" you might like to stop and think:wink:

If you really want to decrease immisions then you get vehicles from A to B as fluidly and as quickly as possible.
TRaffic lights that are designed to stop you on empty roads,short timings and one after the other make more conjestion,as does Speed humps,speed cameras,lane removing, etc etc etc.

As for looking daft,your in danger of it!

If you really want to decrease immisions then you get vehicles from A to B as fluidly and as quickly as possible.
TRaffic lights that are designed to stop you on empty roads,short timings and one after the other make more conjestion,as does Speed humps,speed cameras,lane removing, etc etc etc.



Not quite.

You also need to run the engine at the most efficient speed.

People are allowed to be concerned about anything they choose. What they have reason to be concerned about is quite another matter; and from personal experience, I have never met, or even heard of, anybody who thinks that fining people who break the law is any kind of a problem, or that anyone who is so fined can ever have anyone other than themselves to blame.
You didn't read the Rutland thread on here, then?

There is no excuse for ignorance in the digital age. You might want to check your claim out in a bit more detail.

Unless you are simply trolling, of course.

I would rather be ignorant and laugh at all the gullible people, who believe the governments lies.The world is changing through natural course.There was no factories or cars, that caused the last ice age :roll: Its called climate swings.

Presumably you can provide figures to back this claim.

The monitoring stations at Tinsley have often shown concentrations of NOx double that considered safe.
It is true that these levels went down while the 50mph limit was enforced when the viaduct was being repaired.

I don't have access to figures that say if this was directly as a result of the speed or if less traffic used the viaduct.

Look North covered it twice recently

http://www.youtube.com/watch?v=I0hLFAu4eAM

and

http://www.youtube.com/watch?v=8OejMNrvo6o

That is just what you are being told.

That is just what you are being told.

Well you can believe that , or you can do what we did.

Got hold of the relevant equipment and measured it at various locations round the city.

I suppose you are going to say the equipment we used was rigged next?

You do get the feeling that the council in Sheffield are trying to frustrate people out of their cars.

Totally agree with you about traffic light phasing. I regularly drive through Sheffield at ungodly hours, it is amazing how many lights you get stopped at when there is no other traffic on the road. I can only conclude it is deliberate. Worst example for me is if you drive from the Leadmill area on Sheaf Street to Park Square roundabout. You will generally get stopped at Harmer Lane (where busses turn off to go up to the bus station - bear in mind this is early hours of the morning we're talking about ) - then you will get stopped at the next set of lights (Pond St) before finally getting stopped again at Park Square. Stopped three times for absolutely no reason.

I have wondered about the phasing on those lights. It makes no sense at all, other than disrupting trafflc flow. I just dawdle down there at 15 mph these days.

Suppose you implement this over a 7 mile stretch. At 70 mph it will take you 6 minutes to pass through that zone, at 60mph it will take you 7 minutes and at 50 mph it will take you 8.4 minutes i.e. 40% longer. So surely unless your emissions are more than 40% less at 50 mph than at 70mph, the amount of exhaust you pump out in the area will be more. According to this document (http://esa21.kennesaw.edu/activities/smog-cars/doe-veh-pollutants.pdf), that doesn't seem to be the case. So what is the council's evidence that this move would improve the air quality?

Well you can believe that , or you can do what we did.

Got hold of the relevant equipment and measured it at various locations round the city.

I suppose you are going to say the equipment we used was rigged next?

No,just faulty :hihi:

In any case the thing they were making a big noise about with the air quality monitoring was the fact that Broomhill was somewhere near the top of the worst spot list. What do the council propose to do there?

So does that mean they will increase the A61 Penistone Road from 30 to 50? :hihi: :hihi:

Being stopped by red lights in the early hours of the morning could be avoided by having the ambers flashing, meaning give way to any traffic from the right.

Being stopped by red lights in the early hours of the morning could be avoided by having the ambers flashing, meaning give way to any traffic from the right.

I'm out to work in the very early hours and I go straight through loads of red lights. Only the ones where I can see that there's no other traffic around.

None, as far as law-abiding folk are concerned.

How much money they rake in from law-breakers is of no concern to anyone.

which laws would they be then?

One of the main causes of pollution within Sheffield is the constant stopping and starting of traffic caused by idiotically programmed traffic signals.

It does not need a brain of Britain to program these traffic signals. It is just unfortunate that the traffic management in Sheffield seem to have employed bird brains to program the traffic signals instead.

Yesterday, negotiating the (South) Tinsley roundabout under the M1, I had to pull up at every set of traffic lights. This was not due to any traffic but due to the pathetic phasing of the traffic signals. I was stopped firstly at the signals at the end of the Viaduct, then the lights for Sheffield Road (A6178 towards Rotherham), then the lights for Bawtry Road (A631), then the lights for the M1 south, then the lights for Shepcote Lane (A631) and finally the lights for Sheffield Road (A6178 towards Meadowhall and Sheffield). That is SIX times the lights were at red. Now, I was on my cycle so apart from some perspiration and exhaled carbon dioxide from breathing, very little pollution but what about cars, taxies, lorries and busses having to stop and start each time? THAT is the reason for all the pollution at Tinsley.

Sorting out the traffic light phasing would be a better option for sorting out the pollution than any 50 mph limit on the M1.

this has really annoyed me. they replace the signals with new ones, allegedly better, and immediately, the traffic starts to queue up the sliproad onto the m1, extremely dangerous.

you also have to stop at each set of lights, increasing stop start driving, and frustration, so now, i spend even more time polluting sheffield just trying to get to work.

they have also changed the shared amber phase this reducing traffic throughflow.

but then again, who are we to question how our taxes are being spent!

Not quite.

You also need to run the engine at the most efficient speed.

Which is over 50mph.

Suppose you implement this over a 7 mile stretch. At 70 mph it will take you 6 minutes to pass through that zone, at 60mph it will take you 7 minutes and at 50 mph it will take you 8.4 minutes i.e. 40% longer. So surely unless your emissions are more than 40% less at 50 mph than at 70mph, the amount of exhaust you pump out in the area will be more. According to this document (http://esa21.kennesaw.edu/activities/smog-cars/doe-veh-pollutants.pdf), that doesn't seem to be the case. So what is the council's evidence that this move would improve the air quality?


I notice that the link is to a USA website, and I dont know how it would compare to equivalent UK data, but even this data does support a reduction to 50 mph. There is barely any change in VOCs, but CO and NOx clearly reduce with a drop in speed. There is no need to require a 40% drop in emissions. The emissions are quoted in gram/mile. As the distance covered doesn't change, then any reduction is valid.

What is particularly impressive, though, is the improvement in vehicle emissions, over time.

I notice that the link is to a USA website, and I dont know how it would compare to equivalent UK data, but even this data does support a reduction to 50 mph. There is barely any change in VOCs, but CO and NOx clearly reduce with a drop in speed. There is no need to require a 40% drop in emissions. The emissions are quoted in gram/mile. As the distance covered doesn't change, then any reduction is valid.

What is particularly impressive, though, is the improvement in vehicle emissions, over time.

Hmm, you're right, didn't spot the units. So maybe it would work. Which I'm sure would then raise the question - why not lower all the motorways to a 50mph limit?

People are allowed to be concerned about anything they choose. What they have reason to be concerned about is quite another matter; and from personal experience, I have never met, or even heard of, anybody who thinks that fining people who break the law is any kind of a problem, or that anyone who is so fined can ever have anyone other than themselves to blame.

You have met people though who think that changes in the law that happen to criminalise otherwise perfectly reasonable behaviour is something to be concerned about, right, and people that get concerned about disingenuous changes to the law designed such that people are likely to break it which happens to allow them to be fined?
You seem to have a real blind spot where the law and fines stand, you can't conceive that the law might be wrong or that it might be done deliberately to make money because it's known that people will break it.

Suppose you implement this over a 7 mile stretch. At 70 mph it will take you 6 minutes to pass through that zone, at 60mph it will take you 7 minutes and at 50 mph it will take you 8.4 minutes i.e. 40% longer. So surely unless your emissions are more than 40% less at 50 mph than at 70mph, the amount of exhaust you pump out in the area will be more. According to this document (http://esa21.kennesaw.edu/activities/smog-cars/doe-veh-pollutants.pdf), that doesn't seem to be the case. So what is the council's evidence that this move would improve the air quality?

Even ignoring the units, 8.4 minutes is clearly not 40% more than 7 minutes...

But 8.4 is clearly 40% more than 6 minutes which is what I actually said.

....... you can't conceive that the law might be wrong or that it might be done deliberately to make money because it's known that people will break it.

Tony Blair could and he turned it into an art-form :rant:

But 8.4 is clearly 40% more than 6 minutes which is what I actually said.

Quite true :D

Suppose you implement this over a 7 mile stretch. At 70 mph it will take you 6 minutes to pass through that zone, at 60mph it will take you 7 minutes and at 50 mph it will take you 8.4 minutes i.e. 40% longer. So surely unless your emissions are more than 40% less at 50 mph than at 70mph, the amount of exhaust you pump out in the area will be more. According to this document (http://esa21.kennesaw.edu/activities/smog-cars/doe-veh-pollutants.pdf), that doesn't seem to be the case. So what is the council's evidence that this move would improve the air quality?

Another feature of the data in the link is the pronounced kink corresponding to 55 mph, which appears to apply to all ages of cars. Although I don't know the source, of the data, I'm inclined to think it is very much developed around a 55 mph s[peed limit, and the data for higher speeds is limited, maybe to one or two speeds only, so there isn't a curve, but an abrupt change.

One thing I find increadibly amazing here is why Sheffield City Council are pushing for this, when only 2 miles of the M1 motorway actually run through its boundary. The majority of the M1 in South Yorkshire either runs through Rotherham (which also has the M18) and Barnsley.

One thing I find increadibly amazing here is why Sheffield City Council are pushing for this, when only 2 miles of the M1 motorway actually run through its boundary. The majority of the M1 in South Yorkshire either runs through Rotherham (which also has the M18) and Barnsley.

This is the problem with politicians. The urge to tinker infests every level of politics, and it is far easier for them to introduce new rules and regulations than it is to repeal old ones, or to make life just a little easier for us all. Plus the peasants will notice rules and regulation, it will give the politician a feeling of power. Lowering the speed limit to 50mph will make some politician somewhere fluff their feathers and think "I did that," when in reality all it will do is inconvenience folk for very little return. Hence why they wont bother to sort out the traffic light phasing which is the one thing which will really sort out our air pollution levels. Nobody would really notice it, it would just sort of quietly happen. The more levels of government we get the more tinkering and restricting gets done. Thankfully we don't live in Scotland or Wales so we only have to put up with Westminster, the E.U, the Council and numerous Quangos, which frankly is enough for anyone.

That, and they will be able to put up SPECS and watch the bank balance grow.

[/Cynic]

One thing I find increadibly amazing here is why Sheffield City Council are pushing for this, when only 2 miles of the M1 motorway actually run through its boundary. The majority of the M1 in South Yorkshire either runs through Rotherham (which also has the M18) and Barnsley.

But the bit causing the problem is at Meadowhall, which is in the Sheffield boundary if my OS map is anything to go by.

Totally agree with you about traffic light phasing. I regularly drive through Sheffield at ungodly hours, it is amazing how many lights you get stopped at when there is no other traffic on the road. I can only conclude it is deliberate. Worst example for me is if you drive from the Leadmill area on Sheaf Street to Park Square roundabout. You will generally get stopped at Harmer Lane (where busses turn off to go up to the bus station - bear in mind this is early hours of the morning we're talking about ) - then you will get stopped at the next set of lights (Pond St) before finally getting stopped again at Park Square. Stopped three times for absolutely no reason. I have also noticed Tinsley to be bad, especially Shepcote Lane/Europa Link Road area. Total waste of time and fuel. It simply has to be deliberate, nobody could be so stupid as to phase lights like that by accident.

This.

The lights in Sheffield have no 'green wave' - you cannot time it so that you hit a run of green lights. This is either incompetence or deliberate.

I don't know why the traffic lights on Park Square are even on apart from at peak times.

Also, poor road surfaces don't help - people brake to avoid potholes and generally lose momentum very slightly over each ripple - multiply that by every car in the city and I expect it makes quite a difference.

One thing I find increadibly amazing here is why Sheffield City Council are pushing for this, when only 2 miles of the M1 motorway actually run through its boundary. The majority of the M1 in South Yorkshire either runs through Rotherham (which also has the M18) and Barnsley.

It's because the M1 runs through and area of dense housing, Tinsley, where there are high levels of pollutants which come from the vehicles using the M1.

It's because the M1 runs through and area of dense housing, Tinsley, where there are high levels of pollutants which come from the vehicles using the M1.

The notion that slowing down traffic passing through that section of the M1 to make the air clearer for Tinsley seems ridiculous to me, I'd like to see the evidence the council has that this will work.

ride a bicycle and ignore them all, you would be amazed at the time thats saved doing that

I'd love to but my round trip is too large.

The notion that slowing down traffic passing through that section of the M1 to make the air clearer for Tinsley seems ridiculous to me, I'd like to see the evidence the council has that this will work.

The notion that you use more fuel per mile to travel at 70 rather than at 50 is self-evident. So there is an obvious cost, emissions-wise, attached to this higher speed.
The Council doesn't really need to do a great deal of research to know that this is the case.
Anyway, Look Leeds suggested that the reduction in speed was being considered in order to reduce the incidence of crashes which is a wholly different objective.

The notion that you use more fuel per mile to travel at 70 rather than at 50 is self-evident. So there is an obvious cost, emissions-wise, attached to this higher speed.
The Council doesn't really need to do a great deal of research to know that this is the case.
Anyway, Look Leeds suggested that the reduction in speed was being considered in order to reduce the incidence of crashes which is a wholly different objective.

Engines run more efficiently over 50 mph. Me thinks Sheffield council are petulantly distinguishing themselves from the Tory led government, who are wanting to raise the motorway speed limit around the country, by lowering our bit.

Engines run more efficiently over 50 mph. Me thinks Sheffield council are petulantly distinguishing themselves from the Tory led government, who are wanting to raise the motorway speed limit around the country, by lowering our bit.

Can you supply any evidence to support your claim that engines run more efficiently above 50 mph?

Does anybody else think that the powers-that-be are just bored. They are sat in their council chambers, drinking tea and nibbling biscuits, just thinking of what scheme they can come up with next. "I know Crawford. Lets put a toll on Wordsworth Avenue to stop people getting to work on time" Oooh! What a great idea Finlay.

Bah! We are just the morons who elected em.

It's because the M1 runs through and area of dense housing, Tinsley, where there are high levels of pollutants which come from the vehicles using the M1.

How do you know that the pollutants come from vehicles using the M1????
Is the level of pollutant higher on that bit of the M1 than any other bit??

Could the high levels be caused by the complete mess that has been made of the roads around Meadowhall and the M1 roundabout

How do you know that the pollutants come from vehicles using the M1????
Is the level of pollutant higher on that bit of the M1 than any other bit??

Could the high levels be caused by the complete mess that has been made of the roads around Meadowhall and the M1 roundabout

i wonder how much is from queued cars, i do struggle to believe its caused by the free flowing motorway, rather, the local road networks

Engines run more efficiently over 50 mph. Me thinks Sheffield council are petulantly distinguishing themselves from the Tory led government, who are wanting to raise the motorway speed limit around the country, by lowering our bit.

But they are not at odds with the Govt at all in wishing to improve air quality - they have EU/Govt air quality targets to meet.

How do you know that the pollutants come from vehicles using the M1????
Is the level of pollutant higher on that bit of the M1 than any other bit??

Could the high levels be caused by the complete mess that has been made of the roads around Meadowhall and the M1 roundabout
So do you think vehicles on the motorway don't produce pollutants?

The levels of pollution produced on other parts of the motorway may be similar, higher or lower, that is not Sheffield Council's concern, because it is not in their area and doesn't affect thousands of Sheffield people in their homes and workplaces. Sheffield Council have statutory responsibilities to monitor air quality levels in their area and to take action when pollutants reach unacceptable levels. That's why they are making the request for the speed limit to be lowered. one of the earlier posts in this thread mentioned that during the works on the viaduct, when the limit was 50, pollutant levels were lower, so it's already proven to work.

Average vehicle flows on the M1 are 100,000+ per day, which is far and away the highest on any road in the area. The motorway is a major contributor to the levels of pollution in the area and I can't see any way you can argue with that.

There are a lot of times when cars have to stop/start in Sheffield but as frustrating as that is, personally attacking transport planners like some of you have here ('birdbrained') is really pathetic and also overlooks two points which some of you persistently seem to forgett when it comes to controlled traffic light systems.

a) There are more people on the roads than just yourselves. If you've stopped at a red light then chances are there are another set of lights, on green, allowing other people through or on to the road. Before you say it, instances of being sat at a red light in the middle of the night when there are no other cars around can be explained by the second point;

b) If you want traffic lights to work together even moderately well, let alone seamlessly, then be prepared to spend a lot of money on technology and manpower. There are a LOT of traffic-light-controlled junctions in Sheffield and to have a man controlling each one or to have the technology to link them all seamlessly is never going to happen. The council, like most others in the UK have done this to an extent but resources are scarce and a perfect system or even one which would just at the very least satisfy the naysayers on this forum is probaby prohibitively expensive or too complex to exist in a practical way.

It really is inconceivable given the conflicting road uses and limited resources & technology to expect them to work together seamlessly for your journey, unless some of you genuinely expect every light to turn green as you approach - selfish much?

I really do think that 90% of most journeys are probably 50:50 when it comes to getting green or red lights but of course, people never remember, notice or rave about the times when things go right.

I'm just annoyed that some of you seem to think Transport Planners are out to ruin your lives. They probably just want to try and do a good job at work like you lot do too but like most of us, don't have the resources, time or technology to do what we'd like to. I suspect they have to stop at red lights on their way home too.

Perhaps we can restrict it to 20 mph and put speed bumps on it in t'sheff section. That should get investment flowing into the region.

There are a lot of times when cars have to stop/start in Sheffield but as frustrating as that is, personally attacking transport planners like some of you have here ('birdbrained') is really pathetic and also overlooks two points which some of you persistently seem to forgett when it comes to controlled traffic light systems.

a) There are more people on the roads than just yourselves. If you've stopped at a red light then chances are there are another set of lights, on green, allowing other people through or on to the road. Before you say it, instances of being sat at a red light in the middle of the night when there are no other cars around can be explained by the second point;

We all use different routes though and it's quite obvious that there are many that do not flow well in any possible direction.
b) If you want traffic lights to work together even moderately well, let alone seamlessly, then be prepared to spend a lot of money on technology and manpower. There are a LOT of traffic-light-controlled junctions in Sheffield and to have a man controlling each one or to have the technology to link them all seamlessly is never going to happen. The council, like most others in the UK have done this to an extent but resources are scarce and a perfect system or even one which would just at the very least satisfy the naysayers on this forum is probaby prohibitively expensive or too complex to exist in a practical way.
This is a poor excuse, the council should stop sticking so many lights in without thinking about co-ordination.

It really is inconceivable given the conflicting road uses and limited resources & technology to expect them to work together seamlessly for your journey, unless some of you genuinely expect every light to turn green as you approach - selfish much?
Nobody is expecting that, but having stopped at one red light it's not good design to make that same block of traffic stop at the next 6 as well.

I really do think that 90% of most journeys are probably 50:50 when it comes to getting green or red lights but of course, people never remember, notice or rave about the times when things go right.
I noticed a green wave going from Shalesmoor to the parkway a few weeks ago, the timings in the morning seem to be completely different to the ones in the evening.

I'm just annoyed that some of you seem to think Transport Planners are out to ruin your lives. They probably just want to try and do a good job at work like you lot do too but like most of us, don't have the resources, time or technology to do what we'd like to. I suspect they have to stop at red lights on their way home too.
I'm not convinced, maybe you're right, or maybe they all hate cars and won't be happy until we're all wearing hair skirts and riding on a bus.

Perhaps we can restrict it to 20 mph and put speed bumps on it in t'sheff section. That should get investment flowing into the region.

Dont forget to add speed cameras to top up the coffers too. We all know how sheffield love their speed cameras.

The notion that you use more fuel per mile to travel at 70 rather than at 50 is self-evident. .

That's not entirely true..it depends on how you are driving..I have an instantaneous mpg reader in my car and I can get better consumption at 70 than at 50 depending on my style of driving at the time...how much more fuel will be used when accelerating back up to 70 from 50 than you would have used had you stayed at a steady 70?

That's not entirely true..it depends on how you are driving.....and the car, obviously :)
I have an instantaneous mpg reader in my car and I can get better consumption at 70 than at 50 depending on my style of driving at the timeI do too and, in same conditions on a same road, have a better mpg figure at 50 in 5th, than at 70 in 6th (or 50 in 6th, for that matter). Best economy possible on that section is 60 in 6th. Diesel manual model with cruise control, and my comment is in respect of driving with cruise control on (best economy).

But then, the thread is about a best-fit measure applicable to all, not suitability on a case-by-case basis (which will always yield "exceptions-which-confirm-the-rule") ;)

So far as 50 on the M1 between Tinsley and Rotherham is concerned, it's already around that at rush hour everyday, as a result of the sheer volume of traffic, anyway. And I see innumerable plonkers getting on the M1 southbound at J34, every day of the week, who never go beyond 50 mph until they reach the absolute end of the ramp.

I honestly don't think it's required at all (as in: making it mandatory/enforceable).

...and the car, obviously :)
I do too and, in same conditions on a same road, have a better mpg figure at 50 in 5th, than at 70 in 6th. Diesel manual model with cruise control, and my comment is in respect of driving with cruise control on (best economy).

Go figure.

I have a diesel manual too.I get better consumption at 70 in 6th than at 50 in 5th though...maybe I'm doing it wrong..? :) I very rarely use cruise control..

The notion that you use more fuel per mile to travel at 70 rather than at 50 is self-evident. So there is an obvious cost, emissions-wise, attached to this higher speed.
The Council doesn't really need to do a great deal of research to know that this is the case.
Anyway, Look Leeds suggested that the reduction in speed was being considered in order to reduce the incidence of crashes which is a wholly different objective.

By far the greatest polluters on the road are HGVs which, unless I'm mistaken, have a peak fuel efficiency at around 56mph. Reducing their speed down to 50mph will therefore increase pollution.

jb

ETA: Some figures...
The Effects of Speed on Fuel Consumption of a Heavy Duty Truck Engine:
Idling... 1.9L/hr
37mph... 4L/hr... 15.2mpg
50mph... 6.6L/hr... 9.5mpg
56mph... 8.4L/hr... 7.4mpg
BTAC/IRTE technical trials of June 2000

So, forget what I said earlier, we should be lowering the speed limit for HGVs to 37mph forthwith.

I have a diesel manual too.I get better consumption at 70 in 6th than at 50 in 5th though...maybe I'm doing it wrong..? :)Or maybe the (your or mine) computer is wrong ;)
I very rarely use cruise control..I use it all the time these days, I find it achieves a very significant improvement on mpg (between 5 to 7 mpg more)...and it helps keep me calm behind the wheel :D

I have a diesel manual too.I get better consumption at 70 in 6th than at 50 in 5th though...maybe I'm doing it wrong..? :) I very rarely use cruise control..

Why not try driving at 50 in 6th? Why would you change down to 5th if not intending to accelerate?

That's not entirely true..it depends on how you are driving..I have an instantaneous mpg reader in my car and I can get better consumption at 70 than at 50 depending on my style of driving at the time...how much more fuel will be used when accelerating back up to 70 from 50 than you would have used had you stayed at a steady 70?

Obviously it's possible to make 50 less efficient, but the argument is that when driving efficiently and normally, the car will be more efficient at 50 than at 70. It's all down to physics isn't it, the wind and rolling resistance increases exponentially as speed increases and so more energy is used simply keeping at a constant speed.
The only reason a car is more efficient at 50 than an at 30 is down to gearing and the nature of the engine (which generates a minimum amount of power anyway).

Re: slowing down and accelerating, assuming that you slow down by taking your foot of the accelerator (and not braking) then you will loose very little efficiency to the slow down/accelerate at either side of a 50 zone, since the engine uses no fuel at all whilst you allow it to slow.

Funnily enough I also do a lot of night time driving in Leeds (as I work there) and there is no problem there, come off the motorway and you're on a green light wave all the way into the city centre. Same leaving, once you're on the main road to the M621 you're on greens all the way. Why can't we do the same here?

Funnily enough the M621 is a 50mph zone heading into leeds

Funnily enough the M621 is a 50mph zone heading into leeds

I doubt that the 50 zone is at all related to a green wave of lights.

Not sure why Sheffield'ers are so up in arms about this as how many will be affected? The M1 just passes through, its not a local commuter route :confused:

Not sure why Sheffield'ers are so up in arms about this as how many will be affected? The M1 just passes through, its not a local commuter route :confused:
I think you will find that there is a lot of local commuter use of the M1 in that area.

I doubt that the 50 zone is at all related to a green wave of lights.

eh? Not sure of your point. I'm just saying there's a 50mph Motorway in Leeds so the concept is not exclusive to Sheffield

eh? Not sure of your point. I'm just saying there's a 50mph Motorway in Leeds so the concept is not exclusive to Sheffield

You quoted someone who was talking about a green wave when leaving that motorway.

Motorways that go into cities are commonly reduced to 50 limits aren't they?

Funnily enough the M621 is a 50mph zone heading into leeds

It's a slightly different road to the M1 at Tinsley..there are about 7 junctions on a 2 mile (approx) stretch with quite large bends in the road..the M1 at Tinsley is dead straight....If I recall correctly it's always been a 50 limit from roundabout the Stourton junction..(or has been for a very long time)

I think you will find that there is a lot of local commuter use of the M1 in that area.

I dont know if they do or not but for 1 junction?? not the end of the world is it. Adds a minute to the journey- neither here nor there

Not sure why Sheffield'ers are so up in arms about this as how many will be affected? The M1 just passes through, its not a local commuter route :confused:

If its the stretch where the viaduct is, the two lanes of traffic mean its busier and you could hardly get to 70mph. In fact I can't remember a time when I last managed to get to 70 on here. :confused:

I dont know if they do or not but for 1 junction?? not the end of the world is it. Adds a minute to the journey- neither here nor there

How many times now have we heard this in relation to Sheffield Council's constant speed limit reductions? And how many man-hours have we lost as a result when you tot up the amount of traffic and the number of people being conveyed by it? Quite a few I would say.

If its the stretch where the viaduct is, the two lanes of traffic mean its busier and you could hardly get to 70mph. In fact I can't remember a time when I last managed to get to 70 on here. :confused:

It's quite easy at any time outside of rush hours.

jb

Have the council proof that the pollution they claim exists is actually being produced by motorway traffic rather than the stop start traffic on the lower level of the viaduct and the roundabouts at both ends?

Anyone that has been on the M25 will know that “variable” (http://citytransport.info/PhotoCD/4552_78.jpg)speed limits is nothing new, its all about keeping traffic moving rather than stopping and starting all the time.

Anyone that has been on the M25 will know that “variable” (http://citytransport.info/PhotoCD/4552_78.jpg)speed limits is nothing new, its all about keeping traffic moving rather than stopping and starting all the time.

Is that what Sheffield council's proposal is? Doesn't read like that on the link in the firt post on here..sounds like they want a permanent 50 limit on the M1..

Is that what Sheffield council's proposal is? Doesn't read like that on the link in the firt post on here..sounds like they want a permanent 50 limit on the M1..

If its part of traffic management that’s all well and good as it’s the stop starts that cause more pollution, if they want people to go at 50 mph on a empty motorway then they will soon lose public support.

If its part of traffic management that’s all well and good as it’s the stop starts that cause more pollution, if they want people to go at 50 mph on a empty motorway then they will soon lose public support.

To be honest I drive over Tinsley almost every day..there's no problem actually on the motorway there..biggest issue is people queueing to get off at M/hall..not sure how a 50 limit will solve that..

The notion that you use more fuel per mile to travel at 70 rather than at 50 is self-evident. So there is an obvious cost, emissions-wise, attached to this higher speed.
The Council doesn't really need to do a great deal of research to know that this is the case.
Anyway, Look Leeds suggested that the reduction in speed was being considered in order to reduce the incidence of crashes which is a wholly different objective.


Asteady 50mph might be more economical and produce less emissions but that isnt what happens in reality!
Any time you brake or accelerate it wastes energy and nothing more than accelerating costs more fuel,especially from a standstill and thats what happens when you meddle with what is esencially perfectly good running roads.
With the cruise control on at 70 i get near 60mpg,if a reduced speed limit is introduced that WILL be lowered and quite a lot and if the Mpg is reduced then emmisions will go up you would agree with that wouldnt you?
When ever posters like you give examples they are very simplistic and often miles away from what will actually happen which is reduced progress and more fuel/emmisions not that its about emmissions,its about the bigger picture ...pay per mile.
If immisions are really the issue then theres plenty of things could be done that would be far more beneficial than making the traffic hang round an area for quite a bit longer than it was previously.

There are a lot of times when cars have to stop/start in Sheffield but as frustrating as that is, personally attacking transport planners like some of you have here ('birdbrained') is really pathetic and also overlooks two points which some of you persistently seem to forgett when it comes to controlled traffic light systems.

a) There are more people on the roads than just yourselves. If you've stopped at a red light then chances are there are another set of lights, on green, allowing other people through or on to the road. Before you say it, instances of being sat at a red light in the middle of the night when there are no other cars around can be explained by the second point;

b) If you want traffic lights to work together even moderately well, let alone seamlessly, then be prepared to spend a lot of money on technology and manpower. There are a LOT of traffic-light-controlled junctions in Sheffield and to have a man controlling each one or to have the technology to link them all seamlessly is never going to happen. The council, like most others in the UK have done this to an extent but resources are scarce and a perfect system or even one which would just at the very least satisfy the naysayers on this forum is probaby prohibitively expensive or too complex to exist in a practical way.

It really is inconceivable given the conflicting road uses and limited resources & technology to expect them to work together seamlessly for your journey, unless some of you genuinely expect every light to turn green as you approach - selfish much?

I really do think that 90% of most journeys are probably 50:50 when it comes to getting green or red lights but of course, people never remember, notice or rave about the times when things go right.

I'm just annoyed that some of you seem to think Transport Planners are out to ruin your lives. They probably just want to try and do a good job at work like you lot do too but like most of us, don't have the resources, time or technology to do what we'd like to. I suspect they have to stop at red lights on their way home too.

If you had bothered to read the posts griping about traffic light phasing, you would notice that we were complaining about being repeatedly stopped one set of lights after another, on the same stretch of road, at night when there are no other vehicles on the road. The lights are clearly timed against motorists. If they are timed against us then it cant be rocket science to time them in favour. I commute to Leeds and can assure you they do not have this problem there, once you are off the M621 you are Greens all the way, same when going to the motorway. The phasing in Sheffield appears to be deliberatly poor and this contradicts the councils alleged desire to reduce air pollution.

To be honest I drive over Tinsley almost every day..there's no problem actually on the motorway there..biggest issue is people queueing to get off at M/hall..not sure how a 50 limit will solve that..

I use that section daily ………. The problem is people doing 70+ mph been funnelled into two lines to get over the viaduct along with the restricted speeds on lorries ……… a lower speed limit from say Thorpe Hesley at one side and the parkway at the other side would allow traffic to flow better at busy times.

Seems to work well down the M42, since the new cameras and signs were put in place traffic actually moves down there.

It's sad that people keep applying the dumb logic that fast gets you there quicker, it only does if the road has the capacity to cope with the volume of traffic at that speed. Otherwise you get gridlock; slow things down a bit when it's busier and things move better.

Seems to work well down the M42, since the new cameras and signs were put in place traffic actually moves down there.

It's sad that people keep applying the dumb logic that fast gets you there quicker, it only does if the road has the capacity to cope with the volume of traffic at that speed. Otherwise you get gridlock; slow things down a bit when it's busier and things move better.

That's a variable limit..not what's being asked for by Sheff. council...and they also use the hard shoulder on the M42...

Seems to work well down the M42, since the new cameras and signs were put in place traffic actually moves down there.

It's sad that people keep applying the dumb logic that fast gets you there quicker, it only does if the road has the capacity to cope with the volume of traffic at that speed. Otherwise you get gridlock; slow things down a bit when it's busier and things move better.

Except that, as pointed out above, that's not what they're proposing to do.

Asteady 50mph might be more economical and produce less emissions but that isnt what happens in reality!
Any time you brake or accelerate it wastes energy and nothing more than accelerating costs more fuel,especially from a standstill and thats what happens when you meddle with what is esencially perfectly good running roads.
With the cruise control on at 70 i get near 60mpg,if a reduced speed limit is introduced that WILL be lowered
Why will it? Are you not capable of slowing down to 50 without using the brake? and quite a lot and if the Mpg is reduced then emmisions will go up you would agree with that wouldnt you?
Yes, if it's lowered then emissions go up, but you have to establish that it will be lowered.
When ever posters like you give examples they are very simplistic and often miles away from what will actually happen which is reduced progress and more fuel/emmisions not that its about emmissions,its about the bigger picture ...pay per mile.
If immisions are really the issue then theres plenty of things could be done that would be far more beneficial than making the traffic hang round an area for quite a bit longer than it was previously.
For example?

The notion that you use more fuel per mile to travel at 70 rather than at 50 is self-evident. So there is an obvious cost, emissions-wise, attached to this higher speed.


But if you go slower you are in the area a longer time. SOmehow I really doubt the council has done an objective analysis weighing these two (and any other factors) to come to a reasoned conclusion. More likely, which is typical of politicians, is they started with a conclusion that we should have a 50 mph limit and then cherry picked the facts to make it appear it is supported by some sort of valid reasoning.

Seems to work well down the M42, since the new cameras and signs were put in place traffic actually moves down there.

It's sad that people keep applying the dumb logic that fast gets you there quicker, it only does if the road has the capacity to cope with the volume of traffic at that speed. Otherwise you get gridlock; slow things down a bit when it's busier and things move better.

What happens to the traffic when it goes from a 50mph limit to a 70 mph limit as at the end of a variable set?

Even someone like you could guess,but heres the fact! It speeds up!Thats not rocket science is it?So if you have all the cars at the front of a queue slowed down to 50 whats going to happen behind?Conjestion is the modern term.
Its a bit like the pace car at a race,once it moves out of the way guess what happens!!

Some people will believe owt!!

So do you think vehicles on the motorway don't produce pollutants?

The levels of pollution produced on other parts of the motorway may be similar, higher or lower, that is not Sheffield Council's concern, because it is not in their area and doesn't affect thousands of Sheffield people in their homes and workplaces. Sheffield Council have statutory responsibilities to monitor air quality levels in their area and to take action when pollutants reach unacceptable levels. That's why they are making the request for the speed limit to be lowered. one of the earlier posts in this thread mentioned that during the works on the viaduct, when the limit was 50, pollutant levels were lower, so it's already proven to work.



Correlation does not equal causation unfortunately. Did they subtract out from the data first all other variations in pollution levels to do this analysis?

Why will it? Are you not capable of slowing down to 50 without using the brake?
Yes, if it's lowered then emissions go up, but you have to establish that it will be lowered.
For example?

Yes im capable of it,but you know as well as i do many arnt and will over brake,from then on the speed is up and down,,stopping and starting and we know what happens to emmisions when that happens dont we?
It will cause more conjestion which is what causes the most emmisions,its all a crock but im sure some will be simple enough to be sucked in be it,the goverment and councils know how stupid people are nowadays,its beyond me who ties their shoe laces in a morning!

Its a bit like the pace car at a race,once it moves out of the way guess what happens!!

Some people will believe owt!!

The pace car is a good analogy, it keeps traffic moving like when there is an incident in a F1 race ………. The alternative is stop start …….. stop start.

Some people will believe owt

None, as far as law-abiding folk are concerned.

How much money they rake in from law-breakers is of no concern to anyone.

Get off your high horse :D

But if you go slower you are in the area a longer time. SOmehow I really doubt the council has done an objective analysis weighing these two (and any other factors) to come to a reasoned conclusion. More likely, which is typical of politicians, is they started with a conclusion that we should have a 50 mph limit and then cherry picked the facts to make it appear it is supported by some sort of valid reasoning.

The analysis of this has already been shown earlier in the thread, the pollution/mile (time isn't the issue, distance is) is lower for a car travelling at 50mph than at 70.

The pace car is a good analogy, it keeps traffic moving like when there is an incident in a F1 race ………. The alternative is stop start …….. stop start.

Some people will believe owt


Yes but their not idiots in the cars are they?

The pace car is a good analogy, it keeps traffic moving like when there is an incident F1 race ………. The alternative is stop start …….. stop start.

Some people will believe owt

It keeps it moving slower.. :) and stops overtaking :)..

The analysis of this has already been shown earlier in the thread, the pollution/mile (time isn't the issue, distance is) is lower for a car travelling at 50mph than at 70.

What's the pollution like from a stationary/idling car on a per mile basis..you know,like the ones stuck on the roundabouts and lower level of Tinsley viaduct..?

Why are you asking me?

Why are you asking me?

I thought you might know...if you don't then it's alright to say so... :)

The analysis of this has already been shown earlier in the thread, the pollution/mile (time isn't the issue, distance is) is lower for a car travelling at 50mph than at 70.

time must be an issue I think - at the extreme end if I travel at zero mph the pollution level will spike to infinite levels per/mile since I never reach the end of the mile. So I would think the pollution/mile takes as a factor the time spent to traverse that mile and perhaps pollution per unit time at a given speed for a given engine type + car type.

Often wondered if our traffic lights are twined. I remember in a thread about woodseats, Planner1 (sorry if it wasn’t you) defended the amount of time pedestrians had to wait for the crossing to turn red to allow them to cross saying all the traffic lights in woodseats are twinned to aid the flow of road traffic through the area.

However, if this is the case, why does it not happen with the lights near the Uni tram stop? On the way from Brookhill down to St Mary’s there are 3 sets of lights within about 100m, all going to red at different times, meaning you get stuck in between them.

I doesnt happen like that in the movies (ie the Italian Job!)
"Twinned" is not the right description. Coordinated is the right word.

The crossings near the uni tramstop are not co-ordinated as I understand it, because that is felt to be the best method of operation at that location. Horses for courses.

Correlation does not equal causation unfortunately. Did they subtract out from the data first all other variations in pollution levels to do this analysis?
No matter where you think some of the pollution is coming from, reducing the emissions from 100,000+ vehicles per day which pass through the area is bound to make some difference. It's a very high proportion of the total daily traffic in the area. As has been said earlier, pollution levels in the area dropped when the 50 limit was in place. That wasn't a coincidence, was it?

Reducing the motorway speed limit is a fairly simple thing to do and the Council are required by law to produce an air quality action plan which looks at all practical ways they can reduce pollution levels in Air Quality Management Areas (AQMA's), which, in Sheffield, is the whole of the city. That's why they are asking the government to consider changing the limit.

No matter where you think some of the pollution is coming from, reducing the emissions from 100,000+ vehicles per day which pass through the area is bound to make some difference. It's a very high proportion of the total daily traffic in the area. As has been said earlier, pollution levels in the area dropped when the 50 limit was in place. That wasn't a coincidence, was it?



It could be, yes. I can imagine pollution levels vary quite a lot as a function of month because traffic does too. How do you know a lot of the reduction was not due to this sort of factor?

The analysis of this has already been shown earlier in the thread, the pollution/mile (time isn't the issue, distance is) is lower for a car travelling at 50mph than at 70.

I think it's about time this thread got some actual official figures and analyses... so here it is.

http://www.eea.europa.eu/themes/transport/speed-limits

Based on a simulation, cutting motorway speed limits from 120 to 110 km/h could deliver fuel savings for current technology passenger cars of 12–18 %, assuming smooth driving and 100 % compliance with speed limits. However, relaxing these assumptions to a more realistic setting implies a saving of just 2–3 %.

Significant fuel savings can be achieved by encouraging drivers to maintain a consistent speed and restrict their speed (eco-driving), including through effective enforcement of speed limits.

Cutting speed can also significantly reduce emissions of other pollutants, particularly reducing NOx and particulate matter (PM) output from diesel vehicles. The safety gains from slower driving are also indisputable...

In summary, whereas heavy goods vehicles speed limits in motorways are in line with the optimum speed in terms of energy and CO2 reductions per vehicle-km (80–90 km/h), decreasing car passenger speed limits in motorways could lead to substantial benefits.

The modelling results also suggest that speed limitations of 80–90 km/h on motorways when entering cities and on city ring roads could significantly reduce both fuel consumption and pollutants emitted, in addition to delivering safety benefits.

jb

It's quite easy at any time outside of rush hours.

jb

Which reinforces my theory that during rush hours, when the traffic is at its highest - and producing more pollutants - the speed limit would already be around 50 mph.

/conspiracy

Which reinforces my theory that during rush hours, when the traffic is at its highest - and producing more pollutants - the speed limit would already be around 50 mph.

/conspiracy

From my experience of that stretch of the M1 it's quite often far lower, or stationary, or sometimes, on a particularly bad day, going backwards.

jb

Mine too. So what the council needs to do is get traffic moving faster on that stretch so it runs at the more efficient speed of 50mph and get it through quicker!

Mine too. So what the council needs to do is get traffic moving faster on that stretch so it runs at the more efficient speed of 50mph and get it through quicker!

Having six lanes on Tinsley Viaduct would probably alleviate the situation.
You would have thought that with a design involving 4,500 sheets of calculations, the writing of three computer programs, five structural analyses by computer, 176 drawings and 239 pages of specification and bills of quantities someone would have had the aforethought to increase the load bearing capacity to allow the passage of 40 ton trucks whilst still allowing all original six lanes to remain open.

jb

I think it's about time this thread got some actual official figures and analyses... so here it is.

http://www.eea.europa.eu/themes/transport/speed-limits



jb

What's clear from the table at the bottom of that document is that the UK already has some of the lowest speed limits in Europe.

Having six lanes on Tinsley Viaduct would probably alleviate the situation.
You would have thought that with a design involving 4,500 sheets of calculations, the writing of three computer programs, five structural analyses by computer, 176 drawings and 239 pages of specification and bills of quantities someone would have had the aforethought to increase the load bearing capacity to allow the passage of 40 ton trucks whilst still allowing all original six lanes to remain open.

jb

Good point. Weren't the lanes reduced to 4 because of the weight issue? If so, was it a case of the bridge not being able to take the weight or the powers that be unwilling to spend the money needed to allow it?

Good point. Weren't the lanes reduced to 4 because of the weight issue? If so, was it a case of the bridge not being able to take the weight or the powers that be unwilling to spend the money needed to allow it?

Yep, it was originally intended to carry six lanes of traffic. This was reduced due to a EU directive to allow 40 ton trucks onto the motorway network.

Incidentally construction began in 1965 yet the upper level wasn't given a full clean bill of health until 1980 after the completion of additional strengthening works. The whole project was a bargain at a mere 14 times the original building cost.

http://www.ciht.org.uk/motorway/m1bridges.htm
http://en.wikipedia.org/wiki/Tinsley_Viaduct

jb

Vehicle Exhaust Pollution is directly related to Vehicle Engine Revolutions.
(High Engine Revs = High Exhaust Emissions)

Stop/Start sequences (high revs in low gears) will kick out a lot of killer fumes,
particularly with Heavy Goods Vehicles.
(High Revs with Little Distance = Concentrated Pollution)

The optimum speed for the lowest pollution and acceptable progress is 56 mph
(provided that 56 mph can be maintained)

Sheffield City Council would do well to experiment with a speed limit of
56 mph between M1 Junctions 33 and 35.

SCC should then do their utmost to try and keep the traffic flowing at 56 mph.
However, that is easier said than done.

But it would help if motorway traffic leaving the M1 at Junction 33 (Catcliffe)
had continuous access to Sheffield Parkway (from Northbound M1) and Rotherway
(from Southbound M1) i.e No Traffic Signals.

Perhaps SCC should start talking to Rotherham Council.
.
.
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time must be an issue I think - at the extreme end if I travel at zero mph the pollution level will spike to infinite levels per/mile since I never reach the end of the mile. So I would think the pollution/mile takes as a factor the time spent to traverse that mile and perhaps pollution per unit time at a given speed for a given engine type + car type.

The only thing to consider is pollution/mile, as you say at 0mph that would become infinite because you would never complete a mile. Obviously you could look at pollution/unit time and also at miles/unit time, but ultimately you'd combine them to get pollution/mile as the most useful measurement of the most efficient speed at which to travel to minimise pollution.

Can you supply any evidence to support your claim that engines run more efficiently above 50 mph?

To be honest it was a bit of a bold assumption by me that I hoped no one would call me on :D but I did find this:

"Engine efficiency peaks in most applications at around 75% of rated engine power"

http://en.wikipedia.org/wiki/Engine_efficiency

Make of that what you will, but I'm guessing that 50mph is below 75% of a lot of vehicles rated engine power.

i thought the lane drop over the viaduct was to make it more efficient for traffic leaving the m1, not due to weight.

No matter where you think some of the pollution is coming from, reducing the emissions from 100,000+ vehicles per day which pass through the area is bound to make some difference. It's a very high proportion of the total daily traffic in the area. As has been said earlier, pollution levels in the area dropped when the 50 limit was in place. That wasn't a coincidence, was it?

Reducing the motorway speed limit is a fairly simple thing to do and the Council are required by law to produce an air quality action plan which looks at all practical ways they can reduce pollution levels in Air Quality Management Areas (AQMA's), which, in Sheffield, is the whole of the city. That's why they are asking the government to consider changing the limit.

The only thing simple is the council empoyees who think everything is so simple,its not and even if emmissions were the motive it wont work.
Show me a motorway with a reduced speed limit that flows along at 50mph!
You cant because it doesnt happen,it just causes bunching,conjestion and more emmisions from braking,accelerating and being stood.

To be honest it was a bit of a bold assumption by me that I hoped no one would call me on :D but I did find this:

"Engine efficiency peaks in most applications at around 75% of rated engine power"

http://en.wikipedia.org/wiki/Engine_efficiency

Make of that what you will, but I'm guessing that 50mph is below 75% of a lot of vehicles rated engine power.

Thats if the traffic would flow at 50 mph but it wont.All speedos are fast for a start by about 4mph at 50 so straight away you can knock that off,then take inot account few drivers will drive bang on the limit so knock a few more mph off ,now your getting nearer the 40 than the 50 and this is the M1 were talking about!

The only thing simple is the council empoyees who think everything is so simple,its not and even if emmissions were the motive it wont work.
Show me a motorway with a reduced speed limit that flows along at 50mph!
You cant because it doesnt happen,it just causes bunching,conjestion and more emmisions from braking,accelerating and being stood.

This proposed speed reduction on this section of M1 is SCC sticking two fingers up to a government it naturally doesn't like.

This proposed speed reduction on this section of M1 is SCC sticking two fingers up to a government it naturally doesn't like.

No its not,its whats to come from other towns i suspect.Its easy to blame this goverment but it was the last one that started the road to pay per mile and its coming no matter who gets in,its just a matter of time.

That's true, driving through Sheffield is such a ball ache but perhaps slowing the traffic down forces people to look at the place rather than drive by without noticing it, clever ploy.What's to look at? The mighty River Don?

No its not,its whats to come from other towns i suspect.Its easy to blame this goverment but it was the last one that started the road to pay per mile and its coming no matter who gets in,its just a matter of time.

No what I'm saying is that the government want to increase the speed limit on the motorways to 80mph; doing the opposite(needlesly) on "their bit" of the M1, SCC are sending a petulant message to the Tory led government, a message of Sheffield is Labour, you dont run Sheffield.

its just another example of local councils making changes to roads when they arent qualified to do so.

what happened to roads and speed limits being set by highways engineers?

No what I'm saying is that the government want to increase the speed limit on the motorways to 80mph; doing the opposite(needlesly) on "their bit" of the M1, SCC are sending a petulant message to the Tory led government, a message of Sheffield is Labour, you dont run Sheffield.
The M1 is not within Sheffield Council's control. It is operated on behalf of the Government (Department for Transport) by the Highways Agency.

That's why SCC are asking the Government to reduce the speed limit. SCC can't make them.

So, there 's nothing petulant in it or anything about sending a message to the Government. The Government require SCC to produce an Air Quality Action Plan, because pollution has reached an unacceptable level. What SCC are doing is asking the Government politely if they would consider lowering the speed limit on the M1, to help tackle the pollution issues in the Tinsley area, a good deal of which results from the Government controlled road.

The M1 is not within Sheffield Council's control. It is operated on behalf of the Government (Department for Transport) by the Highways Agency.

That's why SCC are asking the Government to reduce the speed limit. SCC can't make them.

So, there 's nothing petulant in it or anything about sending a message to the Government. The Government require SCC to produce an Air Quality Action Plan, because pollution has reached an unacceptable level. What SCC are doing is asking the Government politely if they would consider lowering the speed limit on the M1, to help tackle the pollution issues in the Tinsley area, a good deal of which results form the Government controlled road.

Well shut my mouth. Thanks for that. Standing down :)

The M1 is not within Sheffield Council's control. It is operated on behalf of the Government (Department for Transport) by the Highways Agency.

That's why SCC are asking the Government to reduce the speed limit. SCC can't make them.

So, there 's nothing petulant in it or anything about sending a message to the Government. The Government require SCC to produce an Air Quality Action Plan, because pollution has reached an unacceptable level. What SCC are doing is asking the Government politely if they would consider lowering the speed limit on the M1, to help tackle the pollution issues in the Tinsley area, a good deal of which results form the Government controlled road.

when you say REACHED an unacceptable level,since when?

Cars kick out alot less crap nowadays and drivers are activily choosing more efficiant cars so give us the run down of when it was acceptable and when it changed to unacceptable,im a little confused but as you know thats not difficult :)
I see you choose the easy posts to answer and ignore the ones difficult to defend.
without name calling please enlighten us how this below is wrong and how SCC think they can get the traffic flow to be fluid at 50 mph when taking these factors into consideration,maybe they have and emmisions arnt really the goal.
Thats if the traffic would flow at 50 mph but it wont.All speedos are fast for a start by about 4mph at 50 so straight away you can knock that off,then take inot account few drivers will drive bang on the limit so knock a few more mph off ,now your getting nearer the 40 than the 50 and this is the M1 were talking about!

Can't quite believe the amount of conspiracy theories here. The speed limit of 50MPH is purely to reduce the air pollution in the Tinsley area, which due to various factors, including the profile of the viaduct, has some of the worst air pollution problems in Europe. The concentration of Nitrogen Dioxide in the area is well above the maximum limit set for public health.

Fuel usage to overcome air resistance is proportional to the square of the speed, so at 70MPH a vehicle will emit 4900 units of air pollution. If speed is reduced to 50MPH the the same vehicle wil emit only 2500 units of air pollution. That's almost half the amount of pollution. It will certainly make the atmosphere much safer for people living in the area. What's the alternative? Evacuate Tinsley and displace the population to somewhere with an atmosphere that doesn't breach public health limits?