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London ULEZ, Bristol CAZ and Wales 20 mph pushbacks

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The Ham

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That's none too difficult in Bristol because the zone is only about three miles across. The London ULEZ covers almost 700 square miles and radiates up to 20 miles from the centre. Most of the people affected by it need to get into and out of it or simply move within it, rather than get round it.

Which could be a reasonable argument if:
- the M25 didn't exist to get around the ULEZ much more easily than is often the case for towns/cities
- it went from no ULEZ to the current (2nd extension)
- if more than about 15% of cars (nationally, locally is lower than this, due to the ULEZ being in existence) weren't compliant
 

The Ham

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You have to pay more attention to sticking to 20 than you do to what's going on around your car.

Most of the time you're likely to be near(ish) other cars so could gauge your speed from them.

A lot of the time when diving in residential streets you're likely not to be doing more than 20 already. Especially modern estates (anything built in the last 30 years) where they will have been designed to keep your speeds low.
 

stuu

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You have to pay more attention to sticking to 20 than you do to what's going on around your car.
If you can't maintain a steady speed, with occasional glances at the speedo, you should be nowhere near a car
 

The Ham

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If you can't maintain a steady speed, with occasional glances at the speedo, you should be nowhere near a car

Also if you disagree away for 1 second you'll have travelled less distance than at 30 and you'll be able to stop faster, or at least slow to a much lower speed before impact (reducing the severity of the accident significantly).

At 20mph the 0.7 second reaction time from the highest code (and trained traffic cops have said that sort of reaction time is what people can achieve for fairly limited durations, read not driving for much more than 30 minutes without a break and then trained to a much higher standard than the vast majority of people on the roads) is 6m.

Compare that to the 9m at 30mph and at 20 you'll have already started to slow from 20 before you've even reacted at 30.

At 20 it takes to a total of 12m to stop, Vs 23m at 30 (I've not done the maths) but there's a fairly good chance that by the time someone had stopped from 20 a car doing 30 would be still going more than 25mph (certainly more than 20mph).

What I do know is that a car traveling at 40mph would still be doing 30mph by the time a car doing 30 has stopped. Likewise a car doing 80 would still be doing 41mph by the time a car doing 70 would have stopped (and wouldn't have even reacted by the time a car doing 30 has stopped).

Actually when you look at +20mph over the speed limit the numbers are even worse. A car doing 80 in a 60 would still be doing 56mph and a car doing 40 in a 20 would have only just reacted and would still be doing 40mph.

Even small changes can more a significant difference to the speed at impact.
 

squizzler

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Anyway, I'm looking forwards to the government approved car meets in the local business park/retail park, and being able to annoy all those older busy bodies who don't like cars as they are aways stop us from enjoying them.
Hopefully prime minister Sunak the hoon-ac will take part in a few with his low-rider governmental limousine.
 

LNW-GW Joint

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That's quite a misleading map.
It shows the exceptions to the 30-20 rule, which are quite sparse across north Wales, at least.
I also know of several retained-30 zones which aren't on the map.

There's been some half-intelligent thinking in the change, in some areas.
About a decade ago, there was a programme of speed reduction which amounted to extending 30 zones, often to cover adjacent 40 zones, simply by shifting the 30 discs on to the 40 posts. The old 30 posts remained in situ, without discs.
The recent change to 20 in some places has been done by putting 20 discs on the former 30 posts, and leaving the 30 discs in place on the old 40 posts.
So what was 40/30 a decade ago, then 30 throughout, is now 30/20, using the same posts for the division.

For me, there are too many sharp changes in the speed, often 40/20/40 with no 30 gradation.
That promotes phrenetic racing in the 40 sections, whereas before it was a more relaxed gentle speed curve.
So far as I can tell, there has been high conformance to the new limits in my corner of Wales, although quite a few 20 signs have been defaced.
But then we do have a cottage industry in defacing road signs in Wales, if the text isn't to the readers' liking. ;)
Wales is also full of roads where anything higher than 20 is too much for the environment, regardless of the signage.
I think there could be some relaxation of the 20 to 30 in many places, but as we know reversing anything with a safety moniker is hard to do.

The change also does away with the short 20 zones (eg around schools) which were springing up locally, plus the associated road markings and electronic signs (which were often not Highway Code compliant).
So in some ways travel is less "cluttered" with signs than it was.
 
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Krokodil

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Wales is also fill of roads where anything higher than 20 is too much for the environment, regardless of the signage.
And yet we get idiots doing 30mph through a village that has no sidewalks (it's not even part of a through route). As I said earlier, such roads would be better as 20kph, not 20mph.
 

Ediswan

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That's quite a misleading map.
It shows the exceptions to the 30-20 rule, which are quite sparse across north Wales, at least.
It also shows those roads which are reduced to 20 mph (provided the appropriate layers are enabled).
I also know of several retained-30 zones which aren't on the map.
Few maps are perfect. There is probably a disclaimer somewhere.
 

johncrossley

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What has Europe got to do with it. Why not compare with the USA?

In small town America, speed limits are often 25 mph or lower and strictly enforced by police patrols. Small towns are often overpoliced with plenty of bored cops with nothing better to do. As a result, speed limits are respected.
 

yorkie

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Well we certainly do not need Europe to show us how to do things.
Having travelled extensively in Europe, we absolutely do need this.
Can nothing be learned from the successful urban public transport systems in many European cities?
We have a lot to learn.

== Doublepost prevention - post automatically merged: ==

Because we do such a good job ourselves...

Oh, wait!
Quite!

== Doublepost prevention - post automatically merged: ==

I tend to look at the USA for how not to do things. Food safety, firearm laws, public transport; and yes, urban planning.
Very much so!
 

TPO

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In my experience with the Bristol CAZ, most people have cars that can pass through without paying. Those who don’t just drive around it.

Really? Unless you’re driving into the middle of Cardiff, most of the time you’ll be on motorways or rural roads unaffected by the 20 mph zone surely?

Not the case in Wales, a LOT of 20mph on long-distance big A-roads.

No. Only roads that were previously 30mph are now 20, and many which aren't residential have been exempted by local authorities.

Not at all. There's a LOT of long-distance A-roads in south Wales which have a lot of 30mph zones, all of which became 20mph.

I was thinking about this when driving about the other day. There’s actually an awful lot of 30mph in suburban areas. Can be miles and miles of it. That’s a passable trundle if the roads are narrow and busy, but 20mph is really really slow - a third longer journey every time is going to add up.
AIUI getting exemptions in Wales would be hard work - lots of hoops to jump through and the militants like cycling groups are going to object as routine. The irony of course being that the speed limits don’t apply to cyclists so they can whizz through!

Seems to depend on the local authority. Neath-Port-Talbot have done a lot of getting of 30mph orders through for A-road limits to remain at 30mph, then you cross the border into Rhondda Cynon Taff or Carmarthenshire and EVERY previous 30mph is 20mph, often for miles, on main A-roads such as A483, A474 and so on. All the roads (bar A470 dual carriageway) up the valleys are effected.

I would have thought that at 20mph, most diesel and petrol cars will be below their 'sweet spot' in terms of mpg and pollution, anyone able to confirm/ not this? Thus the 20mph figure could actually result in more deaths due to pollution increase, than directly due to collisions.

Depends on the vehicle. In my Big Van, with it's old truck-style big diesel engine lump with a lot of low-down torque it will trundle along at 20mph in 3rd including up (most) hills (of which there are many in Wales). However in my modern fuel-efficient Euro 6 diesel car which gets >70 miles to the gallon, I have to constantly shift between 2nd and 3rd. (I use diesel car as I do a lot of miles for work, I need range, carrying capacity and fuel efficiency).

Also if you disagree away for 1 second you'll have travelled less distance than at 30 and you'll be able to stop faster, or at least slow to a much lower speed before impact (reducing the severity of the accident significantly).

At 20mph the 0.7 second reaction time from the highest code (and trained traffic cops have said that sort of reaction time is what people can achieve for fairly limited durations, read not driving for much more than 30 minutes without a break and then trained to a much higher standard than the vast majority of people on the roads) is 6m.

Compare that to the 9m at 30mph and at 20 you'll have already started to slow from 20 before you've even reacted at 30.

At 20 it takes to a total of 12m to stop, Vs 23m at 30 (I've not done the maths) but there's a fairly good chance that by the time someone had stopped from 20 a car doing 30 would be still going more than 25mph (certainly more than 20mph).

What I do know is that a car traveling at 40mph would still be doing 30mph by the time a car doing 30 has stopped. Likewise a car doing 80 would still be doing 41mph by the time a car doing 70 would have stopped (and wouldn't have even reacted by the time a car doing 30 has stopped).

Actually when you look at +20mph over the speed limit the numbers are even worse. A car doing 80 in a 60 would still be doing 56mph and a car doing 40 in a 20 would have only just reacted and would still be doing 40mph.

Even small changes can more a significant difference to the speed at impact.

The maths is of course correct, but to use the maths to justify the blanket 20mph is I suggest somewhat disingenuous, so lets look at the Real World.

Of all of the people hit by road vehicles in 30mph zones, in how many of those cases was the driver under the influence of drugs/alcohol, on the phone, driving without due care etc?

Where's the detailed analysis/stats?

Unless the driver was obeying the 30mph limit and all other driving laws and STILL the consequences were severe, then quoting calculations is whataboutery, there is a difference between correlation and causation which the maths being presented doesn't take into account.

Point being, that 20mph zones with speed cameras (which will no doubt be the end result) will do not a jot to stop the drivers under the influence, on the phone etc..... or the ones in illegal cars without insurance being hooned along dangerously.......... whereas putting the funding into more traffic policing would be more likely the achieve better prevention of collisions (and other bad driving behaviour, and also other crime such as drug dealing, use of illegal/unsafe cars etc).

No, the 20mph zone is all about Comrade Drakeford's control freak tendency (as his COVID restrictions were too). His policies are entirely consistent with his communist leanings, it's just his lack of honesty about his motives that is grating. Oh, and his lack of provision of alternatives especially outside the Core Valleys network (only 4 trains a day on the HOWL- assuming they are not cancelled- and why not re-open the G-C-G and N&B branches to passenger traffic if you're serious about alternatives?).

Everyone I speak to here in Wales generally takes the line of "we agree with 20mph in residential backstreets, outside schools during school hours etc, but not with a blanket 20mph for miles on A-roads". And yes, contrary to what some say here, there are many areas where that's the case.

A more intelligent and relevant implementation would not have attracted anything like so much ire.


The other issues about the M4.

Apparently the 50mph through Brynglas (and Port Talbot, and on the new stretch of dual carriageway on Heads of the Valleys) is about pollution, however the fact that big vehicles will need to change down to get up the hills tends to undermine this. Similar schemes in England (such as the viaduct on the M1 past Sheffield) are signed at 60mph, so in effect everything trundles along at around 56mph, in the sweet spot and being able to go uphill in top. That works much better. The M4 stretch between jn24 and jn28 has some steep hills for a m-way, so the 50mph vice 60mph does lead to a lot more changing down than if on the flat.

Then some of us recall the Welsh Govt draft policy published online with a very badly publicized and extremely short "consultation" which was about road charging for those stretches of M4 and Heads of the Valleys road where they have 50mph with average cameras on. The general gist was that if they don't get enough of a pollution reduction they will put a ULEZ type charge on those stretches.

A lot of money comes into Wales on the M4 (tourists) and almost all food comes into south Wales on a truck which uses either the M4 through Brynglas or the Heads of the Valleys. Can't see how that is helpful when there's no practical alternatives for road freight coming into Wales at the moment. (One of the challenges of rail freight is a total lack of refrigerated vehicles, this plus a massive shortage of rail freight Locos means that there's no genuine short-term alternative to your food coming into Wales on a truck).

Interesting times.

TPO
 

Dai Corner

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Not at all. There's a LOT of long-distance A-roads in south Wales which have a lot of 30mph zones, all of which became 20mph.
It's the nature of any development alongside a road that counts, not the length or classification. Residential means 20mph.
 

yorkie

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...Everyone I speak to here in Wales generally takes the line of "we agree with 20mph in residential backstreets, outside schools during school hours etc, but not with a blanket 20mph for miles on A-roads"...
That sounds a very reasonable view to me.

As for Drakeford, I won't comment as I don't want to get political in a non-GD thread, so I suggest views relating to his leadership take place in a separate thread (if there isn't one, if anyone wants to create one, you are welcome to do so and feel free to link to it from here)
 

Dai Corner

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That sounds a very reasonable view to me.
And indeed what is supposed to happen. Unfortunately, many 'main roads' have houses alongside them (i.e. are 'residential') so have 20mph limits. And they're not building any new bypasses apart from the £1bn one around Merthyr Tydfil.
 

lachlan

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And indeed what is supposed to happen. Unfortunately, many 'main roads' have houses alongside them (i.e. are 'residential') so have 20mph limits. And they're not building any new bypasses apart from the £1bn one around Merthyr Tydfil.
£1bn? That’s a ridiculous amount of money that really should be spent on public transport and cycling infrastructure
 

The Ham

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Not the case in Wales, a LOT of 20mph on long-distance big A-roads.



Not at all. There's a LOT of long-distance A-roads in south Wales which have a lot of 30mph zones, all of which became 20mph.



Seems to depend on the local authority. Neath-Port-Talbot have done a lot of getting of 30mph orders through for A-road limits to remain at 30mph, then you cross the border into Rhondda Cynon Taff or Carmarthenshire and EVERY previous 30mph is 20mph, often for miles, on main A-roads such as A483, A474 and so on. All the roads (bar A470 dual carriageway) up the valleys are effected.



Depends on the vehicle. In my Big Van, with it's old truck-style big diesel engine lump with a lot of low-down torque it will trundle along at 20mph in 3rd including up (most) hills (of which there are many in Wales). However in my modern fuel-efficient Euro 6 diesel car which gets >70 miles to the gallon, I have to constantly shift between 2nd and 3rd. (I use diesel car as I do a lot of miles for work, I need range, carrying capacity and fuel efficiency).



The maths is of course correct, but to use the maths to justify the blanket 20mph is I suggest somewhat disingenuous, so lets look at the Real World.

Of all of the people hit by road vehicles in 30mph zones, in how many of those cases was the driver under the influence of drugs/alcohol, on the phone, driving without due care etc?

Where's the detailed analysis/stats?

Unless the driver was obeying the 30mph limit and all other driving laws and STILL the consequences were severe, then quoting calculations is whataboutery, there is a difference between correlation and causation which the maths being presented doesn't take into account.

Point being, that 20mph zones with speed cameras (which will no doubt be the end result) will do not a jot to stop the drivers under the influence, on the phone etc..... or the ones in illegal cars without insurance being hooned along dangerously.......... whereas putting the funding into more traffic policing would be more likely the achieve better prevention of collisions (and other bad driving behaviour, and also other crime such as drug dealing, use of illegal/unsafe cars etc).

No, the 20mph zone is all about Comrade Drakeford's control freak tendency (as his COVID restrictions were too). His policies are entirely consistent with his communist leanings, it's just his lack of honesty about his motives that is grating. Oh, and his lack of provision of alternatives especially outside the Core Valleys network (only 4 trains a day on the HOWL- assuming they are not cancelled- and why not re-open the G-C-G and N&B branches to passenger traffic if you're serious about alternatives?).

Everyone I speak to here in Wales generally takes the line of "we agree with 20mph in residential backstreets, outside schools during school hours etc, but not with a blanket 20mph for miles on A-roads". And yes, contrary to what some say here, there are many areas where that's the case.

A more intelligent and relevant implementation would not have attracted anything like so much ire.


The other issues about the M4.

Apparently the 50mph through Brynglas (and Port Talbot, and on the new stretch of dual carriageway on Heads of the Valleys) is about pollution, however the fact that big vehicles will need to change down to get up the hills tends to undermine this. Similar schemes in England (such as the viaduct on the M1 past Sheffield) are signed at 60mph, so in effect everything trundles along at around 56mph, in the sweet spot and being able to go uphill in top. That works much better. The M4 stretch between jn24 and jn28 has some steep hills for a m-way, so the 50mph vice 60mph does lead to a lot more changing down than if on the flat.

Then some of us recall the Welsh Govt draft policy published online with a very badly publicized and extremely short "consultation" which was about road charging for those stretches of M4 and Heads of the Valleys road where they have 50mph with average cameras on. The general gist was that if they don't get enough of a pollution reduction they will put a ULEZ type charge on those stretches.

A lot of money comes into Wales on the M4 (tourists) and almost all food comes into south Wales on a truck which uses either the M4 through Brynglas or the Heads of the Valleys. Can't see how that is helpful when there's no practical alternatives for road freight coming into Wales at the moment. (One of the challenges of rail freight is a total lack of refrigerated vehicles, this plus a massive shortage of rail freight Locos means that there's no genuine short-term alternative to your food coming into Wales on a truck).

Interesting times.

TPO

Clearly there's other factors, however even if the speed limits aren't enforced by cameras people have a tendency to self limit, some would do so at 3mph over, others 12mph over.

Even if they increase their self limit by 5mph for a 20 over a 30 then any accident is going to result in a lower impact speed.

Yes there's issues with phone use, drunk drivers, etc. however with the rise of dash cams and cyclists having cameras it's getting harder to get away with things (even if there's no police around). Likewise culturally drink driving is less acceptable amongst younger (under 45) drivers for whom it has always been something you don't do compared to those older drivers (likely noticeable older than 45) for whom it has been the norm to have a swift half and so would risk it if they'd had a little more (note I'm not saying that all older drivers think like this or that no younger drivers drink drive, just the general culture).

Policing of other offences should be a higher priority. There's scope to catch more with ANPR, however with significant cuts to police budgets it is what it is for now.

Whilst I have sympathy for those areas where 20mph limits go on for prolonged distances a lot of highway authorities prefer long lengths of speed limits (for example 1 mile), rather than it changing every few hundred metres.
 

yorkie

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To be fair, they are spending a similar amount on the railways.
I disagree; spending money on increasing road capacity for motorists does not solve any problems; it just encourages more people to drive.
 
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