M1 to be 50mph around Sheffield??

[Xt500 10]

It changed to being unacceptable when SCC declared the whole city an Air Quality Management Area (ie when certain pollutant levels reached trigger points). That meant that they had a statutory duty to produce an Air Quality Action Plan, which sets out how they will try to manage the pollution levels.

 

There was a 50 limit over the viaduct for a substantial length of time when the strengthening works were being carried out. Did we notice any great difference in traffic flows?

 

Still avoiding the issue arnt you?

 

Your an expert arnt you?

 

Whats the normal average speed in a 50mph limit?

 

My GUESS would be 35-40 mph outside peak times and not late at night.Why have a motorway at all?

How much money is this DELAY going to cause business's? Who is going to fund that?

[ptigga 10]

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.

 

I'll give you an objective analysis. Lets do some mathematics!

 

Assume that length of affected stretch of road is 5 miles

 

Time taken to drive 5 miles at 70 MPH = 4 and 20 seconds (260 seconds)

Time taken to drive 5 miles at 50 MPH = 6 minutes (360 seconds)

 

Fuel usage to overcome air resistance is proportional to the square of the speed. Air pollution is (obviously) directonally proportional to fuel usage. It doesn't matter what the units are for the purposes of this exercise.

 

70 x 70 = 4900 units of air pollution emitted by vehicle travelling at 70 MPH

50 x 50 = 2500 units of air pollution emitted by vehicle travelling at 50 MPH

 

4900 * 260 seconds = 1 274 000 units of air pollution emitted over a 5 mile stretch by vehicle travelling at 70MPH

 

2500 * 360 seconds = 900 000 units of air pollution emitted over a 5 mile stetch by vehicle travelling at 50MPH

 

900 000/1 274 000 = 0.7

 

So, as a result of valid mathematical reasoning I conclude that reducing the speed to 50MPH does reduce the air pollution significantly.

[Garbo 10]

have you accounted for stationary traffic on the roads leading to the motorway?

[Xt500 10]

I'll give you an objective analysis. Lets do some mathematics!

 

Assume that length of affected stretch of road is 5 miles

 

Time taken to drive 5 miles at 70 MPH = 4 and 20 seconds (260 seconds)

Time taken to drive 5 miles at 50 MPH = 6 minutes (360 seconds)

 

Fuel usage to overcome air resistance is proportional to the square of the speed. Air pollution is (obviously) directonally proportional to fuel usage. It doesn't matter what the units are for the purposes of this exercise.

 

70 x 70 = 4900 units of air pollution emitted by vehicle travelling at 70 MPH

50 x 50 = 2500 units of air pollution emitted by vehicle travelling at 50 MPH

 

4900 * 260 seconds = 1 274 000 units of air pollution emitted over a 5 mile stretch by vehicle travelling at 70MPH

 

2500 * 360 seconds = 900 000 units of air pollution emitted over a 5 mile stetch by vehicle travelling at 50MPH

 

900 000/1 274 000 = 0.7

 

So, as a result of valid mathematical reasoning I conclude that reducing the speed to 50MPH does reduce the air pollution significantly.

 

Are you stupid?

 

The M1 isnt a machine not is the drivers who use it!

 

Just avoiding it arnt you?

 

The road WILL not flow perfectly at 50mph,you know it,i know it,so how will reducing the speed limit to 50 help?

[ptigga 10]

Are you stupid?

 

No.

 

The M1 isnt a machine not is the drivers who use it!

Pardon?

 

Just avoiding it arnt you?

 

Avoiding what?

 

The road WILL not flow perfectly at 50mph,you know it,i know it,so how will reducing the speed limit to 50 help?

 

Firstly this is not about purely about traffic flow. It's about emissions. Reducing speed is the most effective way to reduce emissions.

 

Secondly reducing the speed to 50 MPH generally improves the flow of traffic because all traffic on the motorway (HGVs and cars) travels at roughly the same speed. There are much fewer changes of speed as vehicles aren't slowing down and speeding back up as much as they would if they were all travelling at different speeds.

 

What is your proposed solution?

[Planner1 438]

yes, the queues joining the m1 were muuuuuch longer and slower.

 

was fine again up until the new signals on the roundabout that have made a total mess again, and change their program almost daily

I don't agree at all.

 

The 50 limit made no difference whatsoever to people joining the motorway.

[Garbo 10]

I don't agree at all.

 

The 50 limit made no difference whatsoever to people joining the motorway.

 

during the works, it was taking me a good 15 minutes to get from the retail park, to the m1.

 

now it takes about 2, well until the most recent change

[Planner1 438]

Still avoiding the issue arnt you?

 

Your an expert arnt you?

 

Whats the normal average speed in a 50mph limit?

 

My GUESS would be 35-40 mph outside peak times and not late at night.Why have a motorway at all?

How much money is this DELAY going to cause business's? Who is going to fund that?

Avoiding what issue?

 

I'm a transport planner, not an air quality expert.

 

How exactly would I know what the normal average speed in a 50 limit is? Do you think there is someone somewhere compiling such statistics? Think again. And, what difference does it make to anything?

 

And taking a minute longer to pass through Tinsley is going to cause what real extra cost to businesses? Remember that vehicles will be going a bit slower, but they will be doing it more economically, so there will be a saving in fuel costs to offset any minor time loss.

 

The cost of the pollution is premature deaths and illnesses. That has a cost to businesses and the nation let's not forget.

[Garbo 10]

when you say you are a transport planner, what does that involve? do you design junctions etc, or is it more general?

 

genuine interest, im not trying to be sarcastic or anything

[Planner1 438]

during the works, it was taking me a good 15 minutes to get from the retail park, to the m1.

 

now it takes about 2, well until the most recent change

Whatever caused that delay was nothing to do with the speed limit on the motorway. Traffic very rarely queues back from the entry slip roads. That only happens when traffic on the motorway has stopped or is crawling along.

[Garbo 10]

Whatever caused that delay was nothing to do with the speed limit on the motorway. Traffic very rarely queues back from the entry slip roads. That only happens when traffic on the motorway has stopped or is crawling along.

 

it was every day for months and months, once on the slips, you could go steadily at about 40 maybe.

 

there is something fundamentally wrong with the local roads around j34, maybe it just cant cope with the traffic.

[Planner1 438]

when you say you are a transport planner, what does that involve? do you design junctions etc, or is it more general?

 

genuine interest, im not trying to be sarcastic or anything

Engineers design junctions, that is a completely different area of work to what I currently do (although I am also a qualified engineer, so I understand all parts of the process).

 

In broad terms, Transport Planners deal with the higher level stuff and Engineers deal with the details. I deal with policies and strategies. I work on building the evidence base to justify the schemes that engineers build. I work on the bids to obtain the funding to pay for the schemes.

 

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