Default 20mph for Wales

hemo
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Location: West Sussex

Re: Default 20mph for Wales

Post by hemo »

It seems not all is well in Wales regarding the new 20 zone, although it is to be enabled I beleive Monmouthshire may not be adjusting some limits and they will remain at 30.
Jdsk
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Re: Default 20mph for Wales

Post by Jdsk »

They're reverting some zones after trials:
https://www.dailymail.co.uk/news/articl ... klash.html

This is different from next year's plans, although I expect that the experience will affect the selection of areas.

Jonathan
Albrecht
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Joined: 26 Jul 2022, 8:47pm

Re: Default 20mph for Wales

Post by Albrecht »

Jdsk wrote: 3 Aug 2022, 7:55pmThey're reverting some zones after trials Daily Mail article.

This is different from next year's plans, although I expect that the experience will affect the selection of areas
While I'm somewhat gratified at reading a comment regarding trucks and inappropriate gear ratios on hills (told ya so), I have to say much of the article is at an idiotic level. "Drivers Rights" are about the closest thing the moron Right have to politically weaponise in this country (excuse the pun), as gun rights are in the USA.

One mom complained and was sufficiently motivated to start a petition against it because, "the move will lead to bikes overtaking cars" .... ???.

And why precisely is that a bad thing?

I would have thought it was a big plus.

It's funny but I have often found some hot hatch driver racing me, dare I overtake him in a traffic queue.

If you look at the pattern of resistance against the trafficking calming bollards, and low-traffic neighbourhoods, initially a large proportion of residents are against it but after a few months, it basically drops to zero when the pluses become obvious. There are groups of men (the cameras always pick up men) going around smashing them up, vandalising them, cutting down the trees in them.

In the meanwhile, if you need to get your granny to the hospital, leave 5 minutes earlier.

I'd like to see some empirical research on what such scheme achieve, e.g. whether they really change journey speeds or cause traffic bottle necks. I'd suspect any differences boil down to a matter of seconds.

The worst result would be if we end up with a patchwork of 20, 30, 40, and part-time speed limits, as the article suggests. I largely gave up driving in the city precisely because of that. My attention was no longer on the road but distracted by confused, ever changing limits or road markings, and the fear of being caught by a camera.
Last edited by Albrecht on 4 Aug 2022, 9:06pm, edited 1 time in total.
Jdsk
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Re: Default 20mph for Wales

Post by Jdsk »

Albrecht wrote: 4 Aug 2022, 8:52pmI'd like to see some empirical research on what such scheme achieve, e.g. whether they really change journey speeds or cause traffic bottle necks. I'd suspect any differences boil down to a matter of seconds.
"20mph Research Study":
https://assets.publishing.service.gov.u ... report.pdf
https://www.gov.uk/government/publicati ... s-on-roads

"Effects of 20 mph interventions on a range of public health outcomes: A meta-narrative evidence synthesis":
https://www.sciencedirect.com/science/a ... via%3Dihub
Plain language summary:
https://evidence.nihr.ac.uk/alert/twent ... -cyclists/

It seems to be very important to distinguish the effects of 20 mph zones and 20 mph limits.

Jonathan
Albrecht
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Joined: 26 Jul 2022, 8:47pm

Re: Default 20mph for Wales

Post by Albrecht »

Jdsk wrote: 4 Aug 2022, 9:04pmIt seems to be very important to distinguish the effects of 20 mph zones and 20 mph limits.
What's the difference?

Thanks, I'll make time for the longer read later.

Here's the executive summary;
"One London study found 20mph zones were associated with reductions of 41.9% in all casualties"
Big win, surely.
Increase in journey times for a 2 mile trip

Residential: 12 seconds
City centre: 24 seconds

Increase in journey times for a 5 mile trip

Residential: 24 seconds
City centre: 54 seconds
Negligible. Barely enough time for the average driver to take a sneaky, surreptitious look at their Facebook status.
It's worth pointing out that delay at junctions can have more of an impact on overall journey times and is unlikely to be affected by the 20mph limits.
Last edited by Albrecht on 4 Aug 2022, 9:21pm, edited 1 time in total.
Jdsk
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Re: Default 20mph for Wales

Post by Jdsk »

Albrecht wrote: 4 Aug 2022, 9:18pm
Jdsk wrote: 4 Aug 2022, 9:04pmIt seems to be very important to distinguish the effects of 20 mph zones and 20 mph limits.
What's the difference?
From the first paragraph of the NIHR plain language summary cited above:

"Speed zones use physical obstacles such as road narrowing, speed bumps and chicanes, whereas speed limits only use signs and lines."

Jonathan
Bmblbzzz
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Location: From here to there.

Re: Default 20mph for Wales

Post by Bmblbzzz »

Albrecht wrote: 4 Aug 2022, 8:52pm The worst result would be if we end up with a patchwork of 20, 30, 40, and part-time speed limits, as the article suggests. I largely gave up driving in the city precisely because of that.
A win for everyone, isn't it? Especially when multiplied by the hundreds or hopefully thousands who will make the same decision. :D

(Yes, yes, I did read the last sentence as well.)
Albrecht
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Re: Default 20mph for Wales

Post by Albrecht »

Jdsk wrote: 4 Aug 2022, 9:21pm"Speed zones use physical obstacles such as road narrowing, speed bumps and chicanes, whereas speed limits only use signs and lines."
Sorry, I have not read it all yet.

So that does that mean it's still 30 with bumps and chicanes, or it's 20 but ALSO has bumps and chicanes.

It would be a real plus, and sell the idea, if part of the deal was "a universal 20mph limit (so everyone knows precisely where they stand) PLUS we'll take out all the Super Mario obstacles that make driving in towns a pain".

Temple Grandin became celebrated for her work in increasing animal welfare at slaughterhouses. Now, I know for some, that sounds a bit like getting a medal for being a better Nazi, but one of her ideas was to add curves and bends so that the animals couldn't see in advance the fate that lay in front of them. Unsurprisingly, herds of animals were much happier to walk around a blind corner, than straight down a shoot galley to the gates of hell.

Applying that same philosophical approach to drivers, it seems what causes them the most distress is straining at the leash when they can see a clear road ahead of that that, in nature, they could be speeding along at maximum revs WERE IT NOT for the chains of some socialist big government holding back their progress and liberty to mow down children and cyclists at will.

Therefore, I blame the Romans for all this. For building all those long straight roads instead of leaving up bound by villagey like wynds.

The same should be applied to new road builds, most tighter curves please. No more nothing to 60 drag strips.

Then we change the gear ratios in the cars.
Bmblbzzz wrote: 4 Aug 2022, 10:00pmA win for everyone, isn't it? Especially when multiplied by the hundreds or hopefully thousands who will make the same decision. :D
Appreciate the wit but, sadly, probably not. It's far more likely to weed out the reasonable concerned drivers and encourage the rabidly determined to speed ones.

Now if we can only do something about all of the illegal electric bicycles charging around out city centres. Never believed that I'd come out against speed but these guys are a serious threat. 85kg at 20mph, looking down at their Google Maps app trying to find out where they're dropping off a pizza too. I fear most of them appear to come from nations where the value of life is a lot less than I value mine.
Last edited by Albrecht on 5 Aug 2022, 10:29am, edited 1 time in total.
Jdsk
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Re: Default 20mph for Wales

Post by Jdsk »

Albrecht wrote: 5 Aug 2022, 10:22am
Jdsk wrote: 4 Aug 2022, 9:21pm"Speed zones use physical obstacles such as road narrowing, speed bumps and chicanes, whereas speed limits only use signs and lines."
Sorry, I have not read it all yet.

So that does that mean it's still 30 with bumps and chicanes, or it's 20 but ALSO has bumps and chicanes.
The studies that I cited upthread are about 20 mph limits and 20 mph zones.

Jonathan
Albrecht
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Re: Default 20mph for Wales

Post by Albrecht »

Jdsk wrote: 5 Aug 2022, 10:27amThe studies that I cited upthread are about 20 mph limits and 20 mph zones.
I'll have to read it for myself yet because it's still not clear to me, despite being repeated identically twice.

limits = limits plus no chicanery; zones = limits PLUS chicanery?

Apart from making the manufacturers of front spoilers rich, what did speed bumps ever achieve?

Interesting article by George Monbiot, interesting for me in that it was written in 2005 and was saying the same thing about libertarian politics back then, and it's only gotten worse since. The Anti-Social [rude word removed] in Our Midst. (See below).

At a local level, new parties of anti-LTN candidates have emerged in the last few elections based solely on the issue of removing traffic restrictions from side streets. What should be even more surprising, but isn't, is that some are literally receiving donations, as much as $300,000 in three years, from US based far right/libertarian funders such as the Koch Foundation (which was founded by US oil billionaire at the heart of climate change denial in the US).

Sometimes referred to as the LM Network in the UK, it's described as "a loose collection of individuals and organisations characterised by an anti-environmentalist, apparently libertarian ideology opposing all restrictions on business, science and technology".
But this is not, or not really, an article about speed, or cameras, or even cars. It is about the rise of the anti-social [rude word removed] who believe they should be allowed to do what they want, whenever they want, regardless of the consequences. I believe that while there are many reasons for the growth of individualism in the UK, the extreme libertarianism now beginning to take hold here begins on the road.

When you drive, society becomes an obstacle. Pedestrians, bicycles, traffic calming, speed limits, the law: all become a nuisance to be wished away. The more you drive, the more bloody-minded and individualistic you become. The car is slowly turning us, like the Americans and the Australians, into a nation which recognises only the freedom to act, and not the freedom from the consequences of other people’s actions. We drive on the left in Britain, but we are being driven to the right.
Pete Owens
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Re: Default 20mph for Wales

Post by Pete Owens »

It is indeed important to distinguish between zones and limits - and make it clear that limits are what is required.

Speed bumps are indeed effective at reducing speeds - but they do it in a very bad way by causing drivers to slow down for each bump and accelerate away aftewards. This tends to increase pollution (which is why you often hear misleading claims that lower speed limits cause pollution when it is traffic calming that causes it). Traffic calming measures all tend to be nasty for cyclists and cause problems for buses ambulances and fire engines - this makes them unsuitable for through routes, and priority routes for emergency services. They are also very much more expensive; you simply would not be able to afford to install traffic calming measures at regular intervels along every single road through every sinlgle town and village in Wales.

Speed limits are also effictive at reducing speeds - though the historical restrictions on where 20mph could be installed have tended to mask this. It used to be the case that 20mph limits could only be imposed on streets where speeds were already low (ie the limit was self enforceing). And even though that restriction no longer applies, the police will still object to any 20mph limit on a street where the limit would actually make a difference. This means that in the vast majority of cases of streets where 20mph has been imposed that limit will have had zero effict since traffic speeds were already lower than 20mph. On those cases where 20mph limits have been iimposed on higher speed roads you do indeed see a significant effect.
Jdsk
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Re: Default 20mph for Wales

Post by Jdsk »

Pete Owens wrote: 5 Aug 2022, 12:14pm It is indeed important to distinguish between zones and limits - and make it clear that limits are what is required.

Speed bumps are indeed effective at reducing speeds - but they do it in a very bad way by causing drivers to slow down for each bump and accelerate away aftewards. This tends to increase pollution (which is why you often hear misleading claims that lower speed limits cause pollution when it is traffic calming that causes it). Traffic calming measures all tend to be nasty for cyclists and cause problems for buses ambulances and fire engines - this makes them unsuitable for through routes, and priority routes for emergency services. They are also very much more expensive; you simply would not be able to afford to install traffic calming measures at regular intervels along every single road through every sinlgle town and village in Wales.

Speed limits are also effictive at reducing speeds - though the historical restrictions on where 20mph could be installed have tended to mask this. It used to be the case that 20mph limits could only be imposed on streets where speeds were already low (ie the limit was self enforceing). And even though that restriction no longer applies, the police will still object to any 20mph limit on a street where the limit would actually make a difference. This means that in the vast majority of cases of streets where 20mph has been imposed that limit will have had zero effict since traffic speeds were already lower than 20mph. On those cases where 20mph limits have been iimposed on higher speed roads you do indeed see a significant effect.
The evidence of which I'm aware is cited above. I'd be very interested in any more.

It includes effects on collisions and casualties as well as on vehicle speed.

Jonathan
Albrecht
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Re: Default 20mph for Wales

Post by Albrecht »

Pete Owens wrote: 5 Aug 2022, 12:14pm the police will still object to any 20mph limit on a street where the limit would actually make a difference.
Why is that?

Clearly it won't apply to them. You would have thought they'd be in favour of removing all road bumps and replacing them with signs and cameras.

I concur on speed bumps being a pain for cyclists with many feeling forced out into the middle of the lane to avoid them.
Pete Owens
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Re: Default 20mph for Wales

Post by Pete Owens »

It isn't because none of those studies take into account the systematic bias as to where traffic calming is imposed and where speed limits are imposed nor do they account for the relative costs of each measure. If you only impose 20mph limits on streets where the speed is already lower than 20mph then you don't need to do a before and after study to work out that will have no effect.

If you wanted to make a valid comparrison you would take two towns of broadly similar population, traffic volumes, casualty rates. You would allocate a similar budget to each. On one that would be sufficient to replace the 30 signs with 20 signs on all the boundary streets On the other you could install a small traffic calming zone covering a handful of streets. Then you would compare the effect of each approach on the whole town.
Pete Owens
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Re: Default 20mph for Wales

Post by Pete Owens »

Albrecht wrote: 5 Aug 2022, 12:30pm
Pete Owens wrote: 5 Aug 2022, 12:14pm the police will still object to any 20mph limit on a street where the limit would actually make a difference.
Why is that?
Because they don't want to be called upon to do any enforcement.
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