Wales to introduce widespread 20mph zones

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Chris Bertram
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Re: Wales to introduce widespread 20mph zones

Post by Chris Bertram »

belgarion wrote: Wed Jul 13, 2022 12:16 Fully understand 20mph zones but driving in Scotland last year, the A68 through Jedburgh was painfully long at 20mph.

If the thinking is that they get more compliance of 30 if the zone is set to 20, can they use 25 instead, it would feel a little less painful.

Vince
Speed limits should take account of the function of a road. If it's a main urban through route (e.g. A, B and C roads), there should be a strong presumption against setting a limit lower than 30, and if it's an arterial route and the standard is high enough, a 40 limit should be considered. As someone else above (sorry, forget who) has said, if all roads have the same low speed limit, the sat nav is likely to choose the shortest distance between two points, and some residents of formerly rather quiet roads are going to get awfully het up about it when TomTom starts sending through traffic their way. Unintended consequences, and all that.
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Re: Wales to introduce widespread 20mph zones

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belgarion wrote: Wed Jul 13, 2022 12:16 Fully understand 20mph zones but driving in Scotland last year, the A68 through Jedburgh was painfully long at 20mph.

If the thinking is that they get more compliance of 30 if the zone is set to 20, can they use 25 instead, it would feel a little less painful.

Vince
Also was astonished by this section when I visited Jedburgh last year. Is it the 'worst' stretch of 20 in the country? On a major through route, the road is wide, with relatively few junctions and business access (no residential access I think), good pavements which often have separation from the carriageway. It could easily be a 40 for most of its length with only the short stretch along Bongate that has any residential frontage, all of which have lengthy front gardens and their parking/access on back roads. If you have never driven on it I encourage you to look at it on Streetview - it is a bizzare stretch of 20.

I'm genuinely in favour of a 'presumption of 20' in urban areas but that has to be put alongside sensible use of 30 and 40 as well.
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Re: Wales to introduce widespread 20mph zones

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B1040 wrote: Sun Dec 26, 2021 11:21 Blanket rules are easier to follow and don't result in an expense of explanatory signs, but blanket rules don't take account of individual circumstances.
Residential roads that are not routes across town should probably be 20. I usually don't drive faster than that anyway. One important question is who or what the roads are for.
This is why the 30 limit is based on street lights rather than signs, you don't want people thinking it's safe to try and go 30 along narrow residential streets lines with parked cars, the same as you don't want people to attempt 60 down the lanes.

Most cities with 20mph schemes exempt many higher standard roads, however Cardiff have not even left out roads that seemed under posted as a 30 limit. One 30 limit road had 97% non-compliance with the existing 30mph speed limit and they still lowered it to 20.
In Caldicot, there is now so much tension on the road between those attempting to comply and those driving to the road standard, someone has already been run over by someone overtaking dangerously. :@
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Re: Wales to introduce widespread 20mph zones

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Rob590 wrote: Thu Jul 14, 2022 10:34
belgarion wrote: Wed Jul 13, 2022 12:16 Fully understand 20mph zones but driving in Scotland last year, the A68 through Jedburgh was painfully long at 20mph.

If the thinking is that they get more compliance of 30 if the zone is set to 20, can they use 25 instead, it would feel a little less painful.

Vince
Also was astonished by this section when I visited Jedburgh last year. Is it the 'worst' stretch of 20 in the country? On a major through route, the road is wide, with relatively few junctions and business access (no residential access I think), good pavements which often have separation from the carriageway. It could easily be a 40 for most of its length with only the short stretch along Bongate that has any residential frontage, all of which have lengthy front gardens and their parking/access on back roads. If you have never driven on it I encourage you to look at it on Streetview - it is a bizzare stretch of 20.
This is why I would add to the speed limit setting guidelines, this simple paragraph, that I don't think should be controversial.

"The lowering of a speed limit alone should not be undertaken in response to high levels of non-compliance with the existing speed limit, or in response to one or even several accidents occurring where drivers were exceeding the existing speed limit."

And how about
"Properly set speed limits should give pedestrians a realistic expectation of what speed the majority of traffic is not exceeding."

I also think the lack of a 25mph option is an issue. For example in Bristol. 20 on side streets, 25 on main roads with shops and 30 on non-shop lined main roads.
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Re: Wales to introduce widespread 20mph zones

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belgarion wrote: Wed Jul 13, 2022 12:16 Fully understand 20mph zones but driving in Scotland last year, the A68 through Jedburgh was painfully long at 20mph.

If the thinking is that they get more compliance of 30 if the zone is set to 20, can they use 25 instead, it would feel a little less painful.
Yes, I fully understand them too, as in understand the sort of thought processes that go in to pushing for them everywhere. I don't agree with them in the slightest though (they should be rare exceptions to the norm).
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Re: Wales to introduce widespread 20mph zones

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20 mph as a default in urban areas makes sense to me.

Residential areas, shopping streets? Think of how many roads where a 20 is appropriate.

Compare the number of arterial roads, A, B, or C, where 30 or higher is appropriate.

Passing TROs for a small number of roads is easier than for a large number of roads. Signing arterials with 30/40 repeaters makes far more sense than residential streets. And it makes missing signs at the entrances less of an issue, because, if you're turning, the presumption will be of a lower speed limit.

Unfortunately it looks like the implementation is going to include a lot of those arterial roads as 20s. But that doesn't mean the overall idea is bad.
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Re: Wales to introduce widespread 20mph zones

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solocle wrote: Thu Jul 14, 2022 13:46 20 mph as a default in urban areas makes sense to me.

Residential areas, shopping streets? Think of how many roads where a 20 is appropriate.

Compare the number of arterial roads, A, B, or C, where 30 or higher is appropriate.

Passing TROs for a small number of roads is easier than for a large number of roads. Signing arterials with 30/40 repeaters makes far more sense than residential streets. And it makes missing signs at the entrances less of an issue, because, if you're turning, the presumption will be of a lower speed limit.

Unfortunately it looks like the implementation is going to include a lot of those arterial roads as 20s. But that doesn't mean the overall idea is bad.
But what is the overall real world effect of reducing speed limits to 20? Evidence suggests that you might, on a good day, reduce overall speeds by a massive 1mph if you're lucky, in the absence of oppressive levels of enforcement anyway. Which suggests to me that the money that will be spent on implementing the limits is pretty much wasted. Is it really such a good idea? Even shopping and residential areas will have quiet times when 30 would be both safe and reasonable, but it will now be illegal; should we be criminalising behaviour that is safe and reasonable?
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Re: Wales to introduce widespread 20mph zones

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Chris Bertram wrote: Thu Jul 14, 2022 14:32
solocle wrote: Thu Jul 14, 2022 13:46 20 mph as a default in urban areas makes sense to me.

Residential areas, shopping streets? Think of how many roads where a 20 is appropriate.

Compare the number of arterial roads, A, B, or C, where 30 or higher is appropriate.

Passing TROs for a small number of roads is easier than for a large number of roads. Signing arterials with 30/40 repeaters makes far more sense than residential streets. And it makes missing signs at the entrances less of an issue, because, if you're turning, the presumption will be of a lower speed limit.

Unfortunately it looks like the implementation is going to include a lot of those arterial roads as 20s. But that doesn't mean the overall idea is bad.
But what is the overall real world effect of reducing speed limits to 20? Evidence suggests that you might, on a good day, reduce overall speeds by a massive 1mph if you're lucky, in the absence of oppressive levels of enforcement anyway. Which suggests to me that the money that will be spent on implementing the limits is pretty much wasted. Is it really such a good idea? Even shopping and residential areas will have quiet times when 30 would be both safe and reasonable, but it will now be illegal; should we be criminalising behaviour that is safe and reasonable?
I understand that the generally accepted figure is that a 1mph drop in average speed reduces injuries by 5%, so not to be sniffed at. In Edinburgh, crashes fell by a third although obviously some of that drop would probably have happened anyway.

Road law regularly criminalises behaviour that is 'safe and reasonable' - such behaviour might include waiting on pedestrian crossing zig-zags when nobody is around, running a red light turning left when it's obviously clear to go or even nipping the wrong way up a one way street when it's quiet and clear. But we accept that there must be some degree of absolutism and you can't always simply trust people's judgement, especially en masse.
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Re: Wales to introduce widespread 20mph zones

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Chris Bertram wrote: Thu Jul 14, 2022 14:32
solocle wrote: Thu Jul 14, 2022 13:46 20 mph as a default in urban areas makes sense to me.

Residential areas, shopping streets? Think of how many roads where a 20 is appropriate.

Compare the number of arterial roads, A, B, or C, where 30 or higher is appropriate.

Passing TROs for a small number of roads is easier than for a large number of roads. Signing arterials with 30/40 repeaters makes far more sense than residential streets. And it makes missing signs at the entrances less of an issue, because, if you're turning, the presumption will be of a lower speed limit.

Unfortunately it looks like the implementation is going to include a lot of those arterial roads as 20s. But that doesn't mean the overall idea is bad.
But what is the overall real world effect of reducing speed limits to 20? Evidence suggests that you might, on a good day, reduce overall speeds by a massive 1mph if you're lucky, in the absence of oppressive levels of enforcement anyway. Which suggests to me that the money that will be spent on implementing the limits is pretty much wasted. Is it really such a good idea? Even shopping and residential areas will have quiet times when 30 would be both safe and reasonable, but it will now be illegal; should we be criminalising behaviour that is safe and reasonable?
There are times when 140 mph on a motorway is both safe and reasonable - a nice empty stretch of M6 toll might be a prime candidate. Although it's hard to tell from street view whether the sight lines are good enough for 140.

I've personally deemed 55 mph in a 30 limit both safe and reasonable - as the speed limit didn't apply to me on a pedal cycle - so why stop at 30 mph limits? Why have speed limits at all? It is, after all, incumbent on road users to maintain a safe and reasonable speed at all times, regardless of the limit.

I think it's pretty clear that such a solution is unworkable. But, therefore, merely being able to do a higher speed safely and reasonably under certain circumstances isn't a legitimate argument against a speed limit.

So, quiet times. Noise is a factor, especially on residential roads. But also simple traffic management. Sat Navs will encourage people to stick to main roads if those main roads have a higher speed limit than potential rat runs. Which avoids "shortcut speeding". And avoiding through traffic using junctions in a way they were not designed.
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Re: Wales to introduce widespread 20mph zones

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jnty wrote: Thu Jul 14, 2022 15:07
Road law regularly criminalises behaviour that is 'safe and reasonable' - such behaviour might include waiting on pedestrian crossing zig-zags when nobody is around, running a red light turning left when it's obviously clear to go or even nipping the wrong way up a one way street when it's quiet and clear. But we accept that there must be some degree of absolutism and you can't always simply trust people's judgement, especially en masse.
And generally such laws are bad laws. It may be a matter for pragmatism that as bad as they are a more reasonable approach just isn't practical, but such arbitrary rules should IMO be avoided wherever possible, and certainly their existence should not be used as a justification for going further down that path.

When it comes to speed limits I've always been of the view that they should be a tool to make it easier to prosecute dangerous driving rather than one to try to micromanage behaviour (often for reasons that are purely political).
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Re: Wales to introduce widespread 20mph zones

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Helvellyn wrote: Thu Jul 14, 2022 15:16When it comes to speed limits I've always been of the view that they should be a tool to make it easier to prosecute dangerous driving rather than one to try to micromanage behaviour (often for reasons that are purely political).
This. Exceeding the speed limit stands as a proxy - or at least should - for dangerous behaviour. When speed limits were based on the 85th %ile, you could clearly say that those who exceeded the limit by a significant margin (given that we set limits in 10mph increments) were the real ****-takers who ought to have the book thrown at them. Now they're based on mean average speeds, even that is less clear, and if limits are set artificially low, then the relationship between "speeding" and dangerous behaviour is lost altogether. This is how to bring the law into contempt, IMHO.
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Re: Wales to introduce widespread 20mph zones

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Information gleaned from a FOI request seen online, shows that the 20 areas in Monmouthshire proceeded with no public inquiry and against WAG general advice (my emphasis in bold).


From doc: PROPOSED MCC 20, 30 & 40MPH SPEED LIMIT ORDER PILOT PROJECT
The Welsh Assembly Government’s Circular 24/2009 provides national guidance for Setting local speed limits in Wales. MCC has considered paragraph 5.6 to 5.11 of the Welsh Assembly Government’s Circular 24/2009 in particular 5.7 and 5.10. A decision has been made to depart from this guidance for the following reasons; to create a culture for slower speeds, reducing the number and severity of road casualties and supporting alternative travel modes such as walking and cycling by making the roads less intimidating to non-vehicle users.
The relevant info from the WAG Circular 24/2009:
5.6 Highway authorities may implement 20mph speed limits and zones where appropriate, particularly in residential areas, and this is encouraged and supported by the Welsh Assembly Government. Such limits may either be full time or restricted to specified hours of the day.
5.7 20mph speed limits may be used on trunk roads in exceptional circumstances, generally over short lengths and for limited times of the day.
5.8 To be successful, 20mph speed limits and zones should ideally be self enforcing. Highway authorities should take account of the level of police enforcement required before installing either of these measures and must always formally consult the police when considering their use.
5.9 Where highway authorities introduce 20mph speed limits for part of the day (e.g. around school hours), care should be taken to ensure that signing is clear and unambiguous to drivers.
5.10 20mph speed limits should only be used for individual roads or for a small network of roads. Research indicates that 20mph speed limits should only be used where mean vehicle speeds are 24mph or below or where traffi c calming measures are planned as part of the speed management strategy.
5.11 20mph zones have a proven casualty reduction benefi t and are usually used in town centres, residential areas and in the vicinity of schools. Their purpose is to create conditions in which drivers naturally drive at around 20mph largely due to vulnerable road user activity.

So as I can understand from this, MCC have taken their own route on this and put a blanket 20mph around all areas with little consideration of the advice from the WAG. Text elsewhere in the MCC paper suggested a traffic management strategy is in the works...
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Re: Wales to introduce widespread 20mph zones

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Chris Bertram wrote: Thu Jul 14, 2022 14:32
solocle wrote: Thu Jul 14, 2022 13:46 20 mph as a default in urban areas makes sense to me.

Residential areas, shopping streets? Think of how many roads where a 20 is appropriate.

Compare the number of arterial roads, A, B, or C, where 30 or higher is appropriate.

Passing TROs for a small number of roads is easier than for a large number of roads. Signing arterials with 30/40 repeaters makes far more sense than residential streets. And it makes missing signs at the entrances less of an issue, because, if you're turning, the presumption will be of a lower speed limit.

Unfortunately it looks like the implementation is going to include a lot of those arterial roads as 20s. But that doesn't mean the overall idea is bad.
But what is the overall real world effect of reducing speed limits to 20? Evidence suggests that you might, on a good day, reduce overall speeds by a massive 1mph if you're lucky, in the absence of oppressive levels of enforcement anyway. Which suggests to me that the money that will be spent on implementing the limits is pretty much wasted. Is it really such a good idea? Even shopping and residential areas will have quiet times when 30 would be both safe and reasonable, but it will now be illegal; should we be criminalising behaviour that is safe and reasonable?
Even if there is a 1mph average speed drop, (some roads have even seen the average speed increase) that's not because the very fastest 1-5% are slowing down, not only are the the least likely to slow down, they're the most likely to do harm and they're the ones properly set speed limits are much more efficient at targeting.
Worse still, it's the behaviour of these drivers that people who want this quickly allude to as the reason they support the limit being dropped, that's what's so insidious.
You make exceeding the speed limit much more normal and socially acceptable and it's propagated by people who are most vocal that speed limits should be obeyed and respected.
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Re: Wales to introduce widespread 20mph zones

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ajuk wrote: Thu Jul 14, 2022 18:05
Chris Bertram wrote: Thu Jul 14, 2022 14:32
solocle wrote: Thu Jul 14, 2022 13:46 20 mph as a default in urban areas makes sense to me.

Residential areas, shopping streets? Think of how many roads where a 20 is appropriate.

Compare the number of arterial roads, A, B, or C, where 30 or higher is appropriate.

Passing TROs for a small number of roads is easier than for a large number of roads. Signing arterials with 30/40 repeaters makes far more sense than residential streets. And it makes missing signs at the entrances less of an issue, because, if you're turning, the presumption will be of a lower speed limit.

Unfortunately it looks like the implementation is going to include a lot of those arterial roads as 20s. But that doesn't mean the overall idea is bad.
But what is the overall real world effect of reducing speed limits to 20? Evidence suggests that you might, on a good day, reduce overall speeds by a massive 1mph if you're lucky, in the absence of oppressive levels of enforcement anyway. Which suggests to me that the money that will be spent on implementing the limits is pretty much wasted. Is it really such a good idea? Even shopping and residential areas will have quiet times when 30 would be both safe and reasonable, but it will now be illegal; should we be criminalising behaviour that is safe and reasonable?
Even if there is a 1mph average speed drop, (some roads have even seen the average speed increase) that's not because the very fastest 1-5% are slowing down, not only are the the least likely to slow down, they're the most likely to do harm and they're the ones properly set speed limits are much more efficient at targeting.
Worse still, it's the behaviour of these drivers that people who want this quickly allude to as the reason they support the limit being dropped, that's what's so insidious.
You make exceeding the speed limit much more normal and socially acceptable and it's propagated by people who are most vocal that speed limits should be obeyed and respected.
Thing is, somebody driving at 42 mph in a 30 limit is eligible for a speed awareness course. If you keep it under 50 mph, it's a Fixed Penalty Notice.

In a 20 limit, those figures are 31 mph and 35 mph respectively.

So the really excessive speeders, if they don't slow down somewhat, can far more easily be insta-banned.
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Re: Wales to introduce widespread 20mph zones

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solocle wrote: Thu Jul 14, 2022 13:46 20 mph as a default in urban areas makes sense to me.

Residential areas, shopping streets? Think of how many roads where a 20 is appropriate.
As someone who used to frequently use shopping streets as a pedestrian, I think that adding light-controlled pedestrian crossings would have a much greater benefit to pedestrian safety than reducing the speed limit. A road that has a mix of cars doing 20 and cars doing 35ish isn't at all easy to cross. A road where all the vehicles stop at regular intervals is much safer. (And, of course, the people who actually comply with the 20 limit are the people who were unlikely to hit me anyway!)

(This also has the benefit that it doesn't hold up the movement of traffic at 3am, like a 20 limit does, until someone actually wants to cross the road. Adherence to the limits is almost zero at times when there are few vehicles and fewer pedestrians.)
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Re: Wales to introduce widespread 20mph zones

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Commercial vehicles have trackers that record speeds, which is why most supermarket delivery vans are much slower than they used to be. Perhaps cars will be fitted with such things and, drivers will be fined without the need for cameras.
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Re: Wales to introduce widespread 20mph zones

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SteveA30 wrote: Fri Jul 15, 2022 06:58 Commercial vehicles have trackers that record speeds, which is why most supermarket delivery vans are much slower than they used to be. Perhaps cars will be fitted with such things and, drivers will be fined without the need for cameras.
Yes, this is the general direction of travel thanks to the people who thought speed cameras were an infringement of their human rights; we're now likely to have far worse enforcement methods in terms of infringing on personal privacy.

So, well done to those responsible.
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Re: Wales to introduce widespread 20mph zones

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Chris Bertram wrote: Thu Jul 14, 2022 16:32
Helvellyn wrote: Thu Jul 14, 2022 15:16When it comes to speed limits I've always been of the view that they should be a tool to make it easier to prosecute dangerous driving rather than one to try to micromanage behaviour (often for reasons that are purely political).
This. Exceeding the speed limit stands as a proxy - or at least should - for dangerous behaviour. When speed limits were based on the 85th %ile, you could clearly say that those who exceeded the limit by a significant margin (given that we set limits in 10mph increments) were the real **** who ought to have the book thrown at them. Now they're based on mean average speeds, even that is less clear, and if limits are set artificially low, then the relationship between "speeding" and dangerous behaviour is lost altogether. This is how to bring the law into contempt, IMHO.
The problem with either of those processes is that it depends on speed limits being a tool for road safety, whereas in many areas they are provably not so (see emissions related limits on otherwise perfectly safe roads), so the law is already being used for non-safety based speed enforcement.
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Re: Wales to introduce widespread 20mph zones

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rhyds wrote: Fri Jul 15, 2022 09:46
Chris Bertram wrote: Thu Jul 14, 2022 16:32
Helvellyn wrote: Thu Jul 14, 2022 15:16When it comes to speed limits I've always been of the view that they should be a tool to make it easier to prosecute dangerous driving rather than one to try to micromanage behaviour (often for reasons that are purely political).
This. Exceeding the speed limit stands as a proxy - or at least should - for dangerous behaviour. When speed limits were based on the 85th %ile, you could clearly say that those who exceeded the limit by a significant margin (given that we set limits in 10mph increments) were the real **** who ought to have the book thrown at them. Now they're based on mean average speeds, even that is less clear, and if limits are set artificially low, then the relationship between "speeding" and dangerous behaviour is lost altogether. This is how to bring the law into contempt, IMHO.
The problem with either of those processes is that it depends on speed limits being a tool for road safety, whereas in many areas they are provably not so (see emissions related limits on otherwise perfectly safe roads), so the law is already being used for non-safety based speed enforcement.
Emissions-related limits are not particularly common, and I'd argue are also not really an appropriate use for speed limits.
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Re: Wales to introduce widespread 20mph zones

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Helvellyn wrote: Fri Jul 15, 2022 09:46
rhyds wrote: Fri Jul 15, 2022 09:46
Chris Bertram wrote: Thu Jul 14, 2022 16:32 This. Exceeding the speed limit stands as a proxy - or at least should - for dangerous behaviour. When speed limits were based on the 85th %ile, you could clearly say that those who exceeded the limit by a significant margin (given that we set limits in 10mph increments) were the real **** who ought to have the book thrown at them. Now they're based on mean average speeds, even that is less clear, and if limits are set artificially low, then the relationship between "speeding" and dangerous behaviour is lost altogether. This is how to bring the law into contempt, IMHO.
The problem with either of those processes is that it depends on speed limits being a tool for road safety, whereas in many areas they are provably not so (see emissions related limits on otherwise perfectly safe roads), so the law is already being used for non-safety based speed enforcement.
Emissions-related limits are not particularly common, and I'd argue are also not really an appropriate use for speed limits.
Wales has a number of them such as the A470 at Pontypridd (70mph D2 limited to 50), a limit so out of place for the road conditions they had to put average speed monitoring up and have to keep reminding folks that its actually enforced.

There's also the A494 at Deeside, though you could possibly argue that's congestion management rather than emissions, but the point stands. Once you start using speed limits for non-safety related reasons they become disregarded, because its an obvious and undeniable example of what many drivers have believed for years, that speed limits aren't set with safety in mind but for political reasons.
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