60 mph motorway limits

[Chris Bertram]

Make the most of NSL while is lasts. This is approaching M5 J2. Not long to go now

Really? Why?

[Bryn666]

Make the most of NSL while is lasts. This is approaching M5 J2. Not long to go now

Really? Why?

Air quality, as has been discussed at length.

[Chris Bertram]

Make the most of NSL while is lasts. This is approaching M5 J2. Not long to go now

Really? Why?

Air quality, as has been discussed at length.

So it'll go up again when enough of us are in electric cars?

[A303Chris]

I can't see what all the fuss is about, it is very common in Europe, my experience of France / Belgium / Holland / Spain and Germany that when a motorway goes through an urban area the speed limit becomes 100kph (62mph) or 90kph (56 mph). You hardly notice it on a long journey.

it takes 9 seconds longer to do a mile at 60mph than 70 mph or 15 seconds between 60mph and 80mph

So it is 3 miles between J1 and J2 on the M5, so adding a mile either side of the junction, you are looking at 5 miles, or 45 seconds travelling time. Similar lengths on the M6 (J6 to J7) and M1 (J33 to34), on a long journey are you going to notice it. You could easily lose more time if you caught the signals wrong at a roundabout

[Truvelo]

It's not even that long as the northern end of the new limit is at J1 with the north facing merges still NSL.

[Big L]

It's simple "something must be done - this is something so we will do it" politics. Dropping the limit to 60 will do nothing to change the pollution caused by lorries etc, and I guess will do very very little to change the pollution caused by cars.

There is still plenty of industry around that area spewing fumes and pollution into the atmosphere.

[brummie_rob]

Looks like they aren't enforcing it with cameras so who is going to stick to it rigidly?

[Truvelo]

Looks like they aren't enforcing it with cameras so who is going to stick to it rigidly?

The repeaters have a sprayed out panel below them. I hope it doesn't say average speed check

[Bryn666]

It's simple "something must be done - this is something so we will do it" politics. Dropping the limit to 60 will do nothing to change the pollution caused by lorries etc, and I guess will do very very little to change the pollution caused by cars.

There is still plenty of industry around that area spewing fumes and pollution into the atmosphere.

"Other things also cause a problem so we shouldn't do anything about this problem" is not a policy. Transport is over a third of the UK's total carbon output, and higher speeds on motorways are a contributor to that as well as the increase in particulates from tyres and exhaust.

If we adopted "other things cause also cause a problem so we shouldn't do anything about this problem" we'd all still be burning coal in fireplaces and running leaded cars. You have to make the first move somewhere.

[the cheesecake man]

IMO M1 J33-34 is a complete waste. They've just spent ages giving it a fourth lane and fancy VSL equipment and now they're going to go ahead and give it a fixed limit of 60 anyway - will the MS4s be used to display the 60 or fixed signs?

I don't get this either. A longer section of the M1 (J28 to J34 iirc) was subject to a multi-year peak time 60 limit. The trial was - I think - not a success and we returned to a default 70 limit some years ago now. So now we do it again. What is different this time?

The 60 limit is displayed on MS4s rather than fixed signs even though it's fixed. Two things are different this time: it covers a shorter stretch, and the signs admit it's an air quality move, instead of pretending it's just a normal reduction resulting from peak congestion.

[Conekicker]

Looks like they aren't enforcing it with cameras so who is going to stick to it rigidly?

The repeaters have a sprayed out panel below them. I hope it doesn't say average speed check

Looks the right size for a box brownie repeater. If it is there will be worded signs with the camera symbol further back and on entry slips.

[Big L]

It's simple "something must be done - this is something so we will do it" politics. Dropping the limit to 60 will do nothing to change the pollution caused by lorries etc, and I guess will do very very little to change the pollution caused by cars.

There is still plenty of industry around that area spewing fumes and pollution into the atmosphere.

"Other things also cause a problem so we shouldn't do anything about this problem" is not a policy. Transport is over a third of the UK's total carbon output, and higher speeds on motorways are a contributor to that as well as the increase in particulates from tyres and exhaust.

If we adopted "other things cause also cause a problem so we shouldn't do anything about this problem" we'd all still be burning coal in fireplaces and running leaded cars. You have to make the first move somewhere.

Another problem is that there is no sensible baseline to trial against.

For the last 9 months traffic has been much reduced by covid. For the 4-or-so years immediately prior to that there were roadworks and a very reduced speed limit on the new trial section.

[Bryn666]

It's simple "something must be done - this is something so we will do it" politics. Dropping the limit to 60 will do nothing to change the pollution caused by lorries etc, and I guess will do very very little to change the pollution caused by cars.

There is still plenty of industry around that area spewing fumes and pollution into the atmosphere.

"Other things also cause a problem so we shouldn't do anything about this problem" is not a policy. Transport is over a third of the UK's total carbon output, and higher speeds on motorways are a contributor to that as well as the increase in particulates from tyres and exhaust.

If we adopted "other things cause also cause a problem so we shouldn't do anything about this problem" we'd all still be burning coal in fireplaces and running leaded cars. You have to make the first move somewhere.

Another problem is that there is no sensible baseline to trial against.

For the last 9 months traffic has been much reduced by covid. For the 4-or-so years immediately prior to that there were roadworks and a very reduced speed limit on the new trial section.

https://www.birmingham.ac.uk/research/p ... kdown.aspx

Covid has improved air quality because people haven't travelled. Therefore the question is "how do we prevent returning to the previous unsustainable situation", not "let's go back to before and have a party like nothing happened".

[Conekicker]

Covid has improved air quality because people haven't travelled. Therefore the question is "how do we prevent returning to the previous unsustainable situation", not "let's go back to before and have a party like nothing happened".

I suspect that the answer to that question, at least in part, will be that many people will be working from home in future. So, at least in the short term, traffic flows will be down.

How sustainable that will be is another matter but it would be possibly ill-advised to implement a solution to a problem that might not exist any more. I'm also thinking about CAZs here - very expensive to install and punitive towards drivers - are they really justifiable now? Wouldn't it be better to leave it a year or two until things settle down and then decide on a way forward?

[Micro The Maniac]

Make the most of NSL while is lasts. This is approaching M5 J2. Not long to go now

Huzzah... they've doubled the 30mph limit

[fras]

Don't you just love the "its only a few seconds longer at 60 than 70. Then we get 60 to 50, 50 to 40, 40 to 30 and its always "its only a few seconds longer". I can see 40 mph on motorways soon, or will the demented 20 mph zealots get it down to 20 moh ?

[Bryn666]

Don't you just love the "its only a few seconds longer at 60 than 70. Then we get 60 to 50, 50 to 40, 40 to 30 and its always "its only a few seconds longer". I can see 40 mph on motorways soon, or will the demented 20 mph zealots get it down to 20 moh ?

Meanwhile in the real world, rural motorways will retain 70 mph speed limits, it's only the tiny percentage of urban motorway mileage these air quality limits will affect.

Paranoia about people reducing speed limits, glad that's the only thing worth worrying about in your world. I'd love to only have first world problems to be worried about.

[Big L]

... demented 20 mph zealots ...

Clicky

[doebag]

... demented 20 mph zealots ...

Clicky

Good grief, so sound only travels a maximum of 200 metres then

So 'if' they did, what sort of distance would be required to safely bring traffic travelling at 70mph down to 20mph in staged reductions of the limit.
What sort of pollution/noise increase would be seen with traffic accelerating back up to NSL.

[ManomayLR]

It's an absolutely stupid idea to have a MOTORWAY running at 20.

But I do like how the MS4s are used for the speed limit on smart-motorway stretches. There's also a message "speed limit reduced for air quality" if I'm not mistaken.