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LTN: Our Healthy Streets - Dulwich: Phase 3


bobbsy

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Thanks heartblock, I?ll have a read. The comment from David Metz fits with my gut reaction to some of the assumptions in those PTC manuals. I do think there?s something in the question of where the shift to cycling is coming from. If people are swapping walking for cycling then that?s a net negative on the swapped journeys (in terms of health benefits and traffic congestion): however I guess there?s an argument that there might be a benefit if someone who walks 60% of journeys and drives 40% of journeys now cycles 100% as a result of getting a bike and bike storage. Although the PCT FAQs show that when modelling, the modellers saw a 100% shift in trips as unlikely.


I?d like the data to be based on distance travelled rather than numbers of people or trips, but no one seems willing or able to collect that data.

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I?d like the data to be based on distance travelled rather than numbers of people or trips, but no one seems willing or able to collect that data.


TfL's WebCAT system does something similar that works off time.

https://tfl.gov.uk/info-for/urban-planning-and-construction/planning-with-webcat/webcat-updates?intcmp=25935


Distance actually isn't that great a measure - people are generally pretty bad at judging distances (which is why so many car journeys are <2km), they go off time. It takes x minutes to go from A to B via Method Y. Time is quite heavily weighted in transport models. A minute spent waiting (eg, for a bus) feels a lot longer than a minute spent travelling (especially if there is no info on when that bus will arrive) so wait time is important as is info. The display board showing the bus is only 2 mins away massively helps with perception.


Where this becomes a problem is in modal shift. Let's say you drive 2km and it takes 10 minutes due to traffic. 10 mins in a car is perceived as a large distance - "well it takes 10 mins to drive so it must be miles away".


However it also takes about that long (10-15 mins) to walk it and less to cycle it. But saying to someone that they should try that is often rebuffed because it's a 10-min car trip so that would, by definition, take AGES to walk or cycle (and this is ignoring anything about carrying stuff or disabilities or whatever so there's some leeway).


To get distance with cars, you can combine various data points. ANPR and/or mobile data will give you an approximate route, the vehicle's registered address is known (although that of course is no guarantee that it started its journey there) but that's still not perfect - there is not blanket coverage of ANPR.

On most public transport, distance is irrelevant, it's simply how long you're sitting on the thing for.


Such detail is not necessarily particularly useful, you're more broadly after trends:

x% of cars driving through [location] are from outside the borough

y% of people arriving at [location] do so by bus

average time spent travelling by Method X is...

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Legal - I am presuming the council will have some of that data as now the monitoring strips have gone in (I believe) they can tell how fast the traffic is moving on any road and whether it is free-flowing or crawling along.


It will be very interesting to see what data they present during the review but my concern is that they are going to be very binary on this: i.e. "we reduced traffic within the LTN areas therefore this has been a success" rather than "whilst traffic reduced in areas within the LTN the impact on boundary roads and other roads outside the LTN was negative".


I also fear they have begun preparing to try to sell the middle ground narrative of "we reduced traffic within the LTN areas and traffic shifted to boundary roads....which are designed for more traffic".

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I get that but for some purposes it?s important eg if LTNs reduce car trips by 5% but increase the length of the remaining trips by 40% for example, that?s relevant? Not to mention increase in idling? Surely we need both sets of data?


You see this is where it does get interesting.


If you're doing a long journey, the impact of a more roundabout exit from your house (due to LTNs) onto the major road network is less relevant as a % of journey time. If you're doing a short journey, the % increase in time is very significant - that's the whole point of them to make driving less of a default choice due to the extra time while simultaneously creating a safer space for active travel - but it's still based off time rather than distance.


The idea being that if your journey now takes 20 mins instead of 10, you'd look to find an alternative method. That's largely true of most modal shift although there's other factors like over-crowding on public transport pushing someone to (eg) cycling/driving the journey instead.

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I get that but don't entirely agree. For people that make long journeys, the cumulative effect of various LTNs can be significant. It's not just one LTN that impacts the journey as you leave your house. Particularly where the LTNs block off or serious congest roads that have historically been important arterial routes. You're not adding 10 mins to a long journey, you're adding eg 5 or 6 times 10 mins to the journey. Ask any delivery driver, carer etc.
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Agree with that LA. I took four people to west berkshire recently (could not have gone by cargo bike) and it took me over 100 minutes to get to the M4, 11 miles away from here due to LTN closures around peckham meaning more buses and the oval backing up traffic, and the near round the clock congestion charge also pushing traffic onto the same "main roads" etc


That was probably 45 minutes of unnecessary additional fumes and pollution from my car that London has chosen to inflict on itself.

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The problem is that some of the ?little spaces? are in the wrong places and congest traffic that is travelling for necessary longer journeys that can?t be, and are therefore not being, substituted by public transport or active travel. No problem in principle with the little neighbourhood spaces but the big picture needs to be looked at and balanced against this, a patchwork of isolated projects by individual councils doesn?t work.


That?s one of my concerns.

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There are some narrow streets to the northeast of peckhamrd where cars could not pass each other without pulling in etc some of these are now LTNs. And it?s made a difference. but DV has wide streets together with many sports grounds and a park but very little pt so not the right place at all for LTNs.
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Legal agree - the councils fail to plan between themselves at the councillor level or at the council-to-council level so there's no strategic thinking holding all of this together. Look at Dulwich, it was clear each councillor jumped on the LTN bandwagon to try and force closures in under covid and gave zero consideration to the impact further down the road (in fact Cllr McAsh used the mooted DV closure as a way to lobby residents to get Melbourne Grove closed instead of challenging the DV councillors about the impact on the Goose Green residents).


Abe is right - a journey to the M4 is now a good 15 minutes longer (25% increase) than it used to be because along every route councils have dropped local LTNs that are displacing traffic onto the only routes around London. As much as the focus has been on local implementations it is clear no-one has been giving any thought to the impact on London's ability to keep functioning or whether the collective mass of these interventions is actually making the very problem (pollution) they are trying to solve a lot worse. And given councils are refusing to monitor pollution I think we can probably understand why now.

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heartblock Wrote:

-------------------------------------------------------

> Lastly...

>

> One of the best reads on society, mobility,

> pollution and equality I have read. Grab a coffee

> and read all of it. An excellent piece of work.

>

> https://static1.squarespace.com/static/57a5a729414

> fb58fa3e0e0a6/t/609173a702d0e054885d2ec0/162014507

> 6839/Equitable+Urban+Mobility.pdf


This seems to be a consultancy (an arm of Noble Ltd) and the document is sponsored by Lend Lease. I'm not saying that invalidates it, but considering people are dismissing a paper published in the Journal of Transport and Healthwork, because the author had an unpaid role with a cycling charity....

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Came across some local congestion / traffic flow data here if anyone is interested.

https://www.whatdotheyknow.com/request/scoot_and_atc_data?utm_campaign=alaveteli-experiments-87&utm_content=sidebar_similar_requests&utm_medium=link&utm_source=whatdotheyknow

I'm sure everyone will find a way to use it to prove what ever point they're trying to make ;-)

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'Centric is a neuroscience research lab creating strategies to improve public health.

We work as a research & data driven lab to help organisations make effective decisions for supporting mental and physical health, specifically for communities that are the most susceptible to poor health outcomes'


but more importantly...did you read it?


I though this pertinent and might have helped Southwark plan appropriately


'Understanding the mobility issues of local residents helps identify the micro-solutions/mitigations needed to ensure that large infrastructure changes such as LTNs do not create any new inequities'

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It's interesting to read some of the commentary in the London Cycling Campaign's consultation response to Southwark's Phase 3 request - timing is very interesting as it was submitted 4 days after the first big lockdown of 2020 started.


https://s3.amazonaws.com/lcc_production_bucket/files/13605/original.pdf?1585322217



Firstly that they didn't think Southwark were going far enough:


There is a risk that this scheme does not, as currently designed, fully eliminate

through motor traffic from the residential and other non-distributor roads in the

area. Further consideration should be given to any remaining through routes,

potentially including Dulwich Park in area B, as well as what happens outside

operating hours on Townley Road. Areas A and C should as much as possible see

strong reductions in through motor traffic throughout also.

- The further proposed restrictions in this context are also supported ? particularly

restricting private, through motor traffic on Dulwich Village itself.


And secondly, that they seemed to want to treat Dulwich as some sort of experiment - an LTN petri-dish almost so that future implementations could mitigate any adverse impacts of the schemes....



For this reason, monitoring, both before and after implementation, of air quality,

motor traffic volumes and speeds, cycling and walking volumes and potentially even

footfall and retail vacancy rates of nearby shops on nearby main roads and

residential streets this scheme could impact, would be desirable, up to several years

after the introduction of the scheme, sporadically. This would enable the borough

and other London, and UK, transport bodies, councillors and officers etc. to build up

a valuable evidence base on the results of introducing LTNs, and enable the borough

to build schemes to mitigate any adverse impacts as well as reassure residents and

shopkeepers of the benefits medium and long-term.

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heartblock Wrote:

-------------------------------------------------------

> 'Centric is a neuroscience research lab creating

> strategies to improve public health.

> We work as a research & data driven lab to help

> organisations make effective decisions for

> supporting mental and physical health,

> specifically for communities that are the most

> susceptible to poor health outcomes'


The glossy brochure, (sponsored by property company Lend Lease) is authored by three people who describe their credentials respectively as 'holding an MSc in neuroscience', having 'an arts degree' and finally 'a PhD candidate'.


The individual with the MSc is the 'Lab Director'.


The Centric Lab is the trading name of Noble Research NP Ltd. It's not yet filed any accounts.


None of this mean that one should not consider the publication on it's merits.


But considering that an academic paper, published in a peer reviewed journal by an award winning University Professor has been dismissed on the grounds that they had a voluntary governance role at a cycling charity...

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heartblock Wrote:

-------------------------------------------------------

> Well, close inspection of data, is not

> 'rubbishing' research, it is part of the important

> scientific inspection and critical analysis that I

> teach.

>

> Students are taught to critically review published

> research -Was the data collection valid? Was the

> methodology appropriate? Does the conclusion

> reflect the statistical data?

>

> I only wish that the safety research conducted by

> the German company Chemie Gr?nenthal for their

> sleeping pill- that it marketed around the world

> as safe for everyone, including expectant mothers,

> had been critically reviewed.



To be fair, this:


"No .... she does not have 25 ?peer reviewed? papers. Yes I am going but cannot deal with inaccurate scientific academic reporting. There are articles and there are peer reviewed articles, I speak as a scientist with many international peer reviewed papers. Also I have never been paid or employed by the organisation paying for the research, unlike Rachel."


Is rubbishing someone's research, based not on the grounds of data, but on an inaccurate character assassination.

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Out of interest - 'Peer Reviewed papers' actually means that the papers were published in journals which are ostensibly 'peer reviewed'. As a number of academics have submitted entirely spoof papers to such journals and had them published, as a test of the system, this is not, exactly, an academic gold standard. Indeed, if you put forward a paper which has conclusions consistent with the editorial line your are far more likely to be 'published' - and this will count as publication in a peer reviewed journal (the 'peers' chosen for review are far more likely to be sympathetic to an editorial line). 'Peer Reviewed' Journals are still, it should be remembered, commercial publishers.


Far more telling as a mark of academic quality is whether you paper is subsequently cited by other academics in theirs, (particularly when cited in papers published in other journals) and the frequency of such citations.


I'm afraid also that, with academic papers as with e.g. novels, there is an abundance of log-rolling, where one 'peer' will applaud another's paper and be applauded in return. Most academic specialisms are quite small pools. [And equally, of course, academic feuds are also pursued through the peer review system.]

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But all about cycling again - when most children walk to school. As a non-driving pedestrian female parent, having the boundary roads - which are generally the most direct /unavoidable walking routes prioritised is more important to me than cycle infrastructure.


I sometimes feel we could all have had a more constructive conversation if we'd had a discussion about reducing car usage that focused initially on public transport and walking, and left cycling out of it.


The discussion of peer review reminded me how much I enjoyed the Sunday Philosophy Club /Isabel Dalhousie books. I must dig them out and re-read.



Otto2 Wrote:

-------------------------------------------------------

> Interesting article --

> https://www.transportxtra.com/publications/local-t

> ransport-today/features/69199/do-inclusive-transpo

> rt-strategies-really-consider-the-needs-of-all-

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Have you seen the new leaflet from Dulwich alliance? It is on their Facebook page and is worth a look. Southwark not releasing any information so at least there is some on there.


Personally a bit fed up of not knowing anything other than what we pick up from that sort of Facebook post, or from twitter. Where are all the councillors and why are they not telling us everything rather than just selective bits and pieces?

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