Low Traffic Neighbourhoods?

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Jdsk
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Re: Low Traffic Neighbourhoods?

Post by Jdsk »

Stevek76 wrote:In terms of impact analysis, on a specific level that's very hard to do for these schemes, most traffic models don't operate at such a fine level of detail and basically none are properly equipped to really understand mode shift to and from walk/cycle. Sometimes the best way to assess the impact is to just get on and do it, particularly given how cheap and quick to add/remove these are. Most have been implemented under what's known as an Experimental Traffic Order, a power set out by the RTRA 1984 that allows trial schemes to be the consultation themselves.

Yes, do the experiment. But do it as well as possible, which is difficult, especially as it seems to take 6 months for opinions to settle down. And do it with independent evaluation.

Jonathan
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mjr
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Re: Low Traffic Neighbourhoods?

Post by mjr »

Stevek76 wrote:In terms of impact analysis, on a specific level that's very hard to do for these schemes, most traffic models don't operate at such a fine level of detail and basically none are properly equipped to really understand mode shift to and from walk/cycle.

Oh I think that's being far too kind! The current popular traffic models like TRIPS, ARCADY and so on deliberately ignore walking and cycling routes except for how giving them any extra traffic signal time will increase delays to motorists. Even when travelling along the same route as motorists, literally only motorists count because the results are stated in Passenger Car Units (PCUs) or sometimes Passenger Car Equivalents and, bizarrely, someone cycling is between 0 and 0.5 PCUs (depending on model in use and which lane the cyclist is in) and someone walking is 0 PCUs. This makes no sense when you can get loads of cyclists or even more walkers in the 3.5m x 16m road space allocated to a car travelling at 20mph.

Sometimes the best way to assess the impact is to just get on and do it, particularly given how cheap and quick to add/remove these are. Most have been implemented under what's known as an Experimental Traffic Order, a power set out by the RTRA 1984 that allows trial schemes to be the consultation themselves.

While cheap and quick, I think the ETRO and follow-up TRO if successful still cost many thousands, and that's still money that people will accuse the council of wasting if the experiment fails and they have to remove it, so some councils will only do it if someone else is paying (such as the national Active Travel Fund has during the last year) and some are still very reluctant even then.
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RickH
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Re: Low Traffic Neighbourhoods?

Post by RickH »

mjr wrote:Oh I think that's being far too kind! The current popular traffic models like TRIPS, ARCADY and so on deliberately ignore walking and cycling routes except for how giving them any extra traffic signal time will increase delays to motorists. Even when travelling along the same route as motorists, literally only motorists count because the results are stated in Passenger Car Units (PCUs) or sometimes Passenger Car Equivalents and, bizarrely, someone cycling is between 0 and 0.5 PCUs (depending on model in use and which lane the cyclist is in) and someone walking is 0 PCUs. This makes no sense when you can get loads of cyclists or even more walkers in the 3.5m x 16m road space allocated to a car travelling at 20mph.

The graphics I've seen in a couple of posts on Twitter illustrate (to a reasonably close approximation) the extra capacity in terms of moving people by getting them out of cars.

This one doesn't make allowance for people on foot but includes bus use
(It is a GIF so the animation won't post directly - click the link to see the animation)
https://twitter.com/i/status/1331870165802180609
Schrodinger's Road Space
Schrodinger's Road Space

I can't find where I saw this originally but I had saved a copy of the graphic.
Person Capacity per lane equivalent
Person Capacity per lane equivalent
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Jdsk
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Re: Low Traffic Neighbourhoods?

Post by Jdsk »

Long Read: "Traffic wars: who will win the battle for city streets?":
https://www.theguardian.com/news/2021/mar/25/traffic-wars-who-will-win-the-battle-for-city-streets

Jonathan

PS: I don't like the title, but it is often discussed in those terms.
ratherbeintobago
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Re: Low Traffic Neighbourhoods?

Post by ratherbeintobago »

Headline aside, that’s not a terrible article.

I’d live to know which active travel infra schemes the LTDA has actually supported though…
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Re: Low Traffic Neighbourhoods?

Post by ratherbeintobago »

https://twitter.com/liveablewells/status/1375535590867886081?s=21

A demonstration of the problem.

(As an aside, is it possible to embed tweets on here?)
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[XAP]Bob
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Re: Low Traffic Neighbourhoods?

Post by [XAP]Bob »

ratherbeintobago wrote:https://twitter.com/liveablewells/status/1375535590867886081?s=21

A demonstration of the problem.

(As an aside, is it possible to embed tweets on here?)


Not that I'm aware of.
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Stevek76
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Re: Low Traffic Neighbourhoods?

Post by Stevek76 »

mjr wrote:
Stevek76 wrote:In terms of impact analysis, on a specific level that's very hard to do for these schemes, most traffic models don't operate at such a fine level of detail and basically none are properly equipped to really understand mode shift to and from walk/cycle.

Oh I think that's being far too kind! The current popular traffic models like TRIPS, ARCADY and so on deliberately ignore walking and cycling routes except for how giving them any extra traffic signal time will increase delays to motorists.


That is not entirely correct but I think you're getting a little hung up on traffic engineering models while I was talking about strategic forecasting ones. Tfl's present strategic model has a cycling network model & after the update a few years ago much of the demand workings operate at a much finer disaggregation of person types, one of the reasons for that change was to better handle the differing propensity to cycle in various conditions by different demographics. Some other models around the country have also made some efforts but none really worth speaking of. A few are built where the demand model covers walk & cycle as modes but mostly just there to get 'about the right mode share' coming out of the demand model and little proper detail representation of the travel costs of either.

However the key issue with LTNs is simply the zone sizes in the models and many of the trips they affect start and end in the same zone. There's a few possible ways around it but all tend to amount to a bit of creative 'professional judgement'.

mjr wrote:so some councils will only do it if someone else is paying (such as the national Active Travel Fund has during the last year) and some are still very reluctant even then.


'Many thousands' is cheap compared to most council transport expenditure, and they will likely save that on maintenance relatively quickly as the wear & tear on roads inside the LTN will be massively reduced whilst the wear on the main roads will be a slight increase in the worst case. Really this is just about political will. If the leadership is willing to tackle car dependency these are cheap and effective measures, and if they're really willing there are several revenue raising tools they have in the form of residents parking permits, workplace parking levies and congestion charges that could help fund such things. Unfortunately, far too many fear the 'motorist vote'. It's electioneering mode in Bristol at the moment and Labour are claiming freezing RPZ fees as something they've delivered! :?

mjr wrote:This makes no sense when you can get loads of cyclists or even more walkers in the 3.5m x 16m road space allocated to a car travelling at 20mph


? It's entirely the point of such values. PCU isn't a representation of people moved, it's a representation of road space used. The problem is too much focus on maximising PCU moved but this isn't really an issue with the tools as such more a combination of the people using them and (mostly) the answers other people are demanding from them. Tools are produced to answer the questions being asked, that the tools used in the UK are too motor traffic/highway focused is a function of decades of government funding focused at road building. Even then some do have greater capability, for example the signal junction software Linsig has been able to model and report pedestrian delays for over a decade. I'm not aware of any council* asking for this, either for their own work, or of developers.

*except London again, which even insists upon full agent based simulations in busy areas.
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ratherbeintobago
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Re: Low Traffic Neighbourhoods?

Post by ratherbeintobago »

Unfortunately, far too many fear the 'motorist vote'.


It would be really interesting to know if that’s actually a thing, though; I’m not sure it is, despite what the likes of the LTDA think, especially not in London.

As a total aside, there’s a lovely TfGM video that I think needs sharing as widely as possible.

[youtube]ZUvqCgfY6lU[/youtube]
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Re: Low Traffic Neighbourhoods?

Post by MikeF »

Pedestrians and cyclists are traffic. As they occupy far less space to move around than cars should High Traffic Zones be the aim? :wink:
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Re: Low Traffic Neighbourhoods?

Post by ratherbeintobago »

Khalid Mahmood currently making an utter tit of himself on Twitter about LTNs, and dismissing anyone who disagrees with him as "woke bourgeoisie" :roll:
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Re: Low Traffic Neighbourhoods?

Post by mjr »

ratherbeintobago wrote: 17 May 2021, 1:40pm Khalid Mahmood currently making an utter tit of himself on Twitter about LTNs, and dismissing anyone who disagrees with him as "woke bourgeoisie" :roll:
Who he? Edit: oic https://www.theyworkforyou.com/mp/11087 ... perry_barr

Some bright sparks have suggested rebranding them to "Active Neighbourhoods". I guess the car-polluted ones then become dead neighbourhoods in name too.
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ratherbeintobago
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Re: Low Traffic Neighbourhoods?

Post by ratherbeintobago »

mjr wrote: 17 May 2021, 1:45pm
ratherbeintobago wrote: 17 May 2021, 1:40pm Khalid Mahmood currently making an utter tit of himself on Twitter about LTNs, and dismissing anyone who disagrees with him as "woke bourgeoisie" :roll:
Who he?

Some bright sparks have suggested rebranding them to "Active Neighbourhoods". I guess the car-polluted ones then become dead neighbourhoods in name too.
West Mids Lab MP who recently stepped down from the shadow cabinet because he felt it was too in thrall to "wokery", which may be true, but in this context appears to mean "things Khalid Mahmood doesn't agree with"

Not sure what branding would help (if it helps at all), but I note that a survey found 25,000 old modal filters (including some near my house) which no-one is suggesting get ripped out to create more rat runs.
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