LTN Discussion

[heartblock]

It only needs to be measured at peak times when hundreds of CYP are walking to school down ED Grove past idling traffic. It would not be expensive and Southwark could spend some of the money from fines - they seen to have accrued a lot.

The question is why doesn't everyone on this thread want to see the NOx and PM levels all these children are breathing in 5 days a week? Knowing the developmental effects on heart, lungs and brain tissue....wouldn't you want to know?

[Bic Basher]

Metallic Wrote:

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

> alice Wrote:

> --------------------------------------------------

> -----

> > Back on subject: Looks like Libdems are now

> > against Dulwich LTNs. Good.

>

> Don't be naive. Their Southwark policy will not

> allow them to do what they are claiming. Look at

> the northern Southwark LibDems!

From what I can see, the Southwark Lib Dems have looked at each one individually, for example they supported the Borough LTN, but they've seen the Dulwich LTN not fit for purpose.

[kissthisguy]

Re 'shipping container sized pollution monitors' things have thankfully moved on in terms of granularity of monitoring and monitor size. The newish monitor on Peckham Road is about the size of a FTTC Cabinet, ie the green Openreach boxes you see on the pavement. It has a periscope-style sensor poking out and monitors the following pollutants:

Nitric Oxide (ug/m3)

Nitrogen Dioxide (ug/m3)

Oxides of Nitrogen (ug/m3 as NO2)

PM1 Particulate (by FDAS) (ug/m3)

PM10 Particulate (by FDAS) (ug/m3)

PM2.5 (not reference equiv.) (by FDAS) (ug/m3)

PM2.5 Particulate (by FDAS) (ug/m3)

Total Suspended Particulate (by FDAS) (ug/m3)

so significantly more sophisticated than diffusion tubes. Other posters like @penguin68 and @spartacus have given a good account of how pollution calculations can be made but perhaps this by Jeff Smith, a pollution expert

sums it up best with ref to LTNs:

"If drinking water was causing this many hospitalizations, there would be riots in the streets. Instead myopic community leaders forced slower & ⬆️polluting traffic onto #London roads as an emergency pandemic response. They didn't collect #AirPollution data before the new #LTNs.

There are some LTNs that can be deployed if proper baseline data is collected in advance. Clearly, the LTNs foisted on communities as a pandemic response are far more likely to cause more #AirPollution than they prevent... & that too along the boundary & larger main roads.

They only used car counts & annual averages of #AirPollution metrics. This is a flawed method.

They need to place the roadside real-time monitors AND use Google maps traffic data to identify the before vs after traffic congestion. We can model exposures with these datapoints."

Food for thought...

redpost Wrote:

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

> heartblock Wrote:

> --------------------------------------------------

> -----

> > And back to LTNs.. does anyone know when

> Southwark

> > will release any data on pollution levels (NOx

> and

> > PM) - although the Mayor has answered a

> question

> > about ED Grove pollution monitors, by

> indicating

> > there is no direct monitoring on ED Grove - can

> > this be confirmed?

>

> Do you see a small shipping sized container

> construction on EDG? Because this is what a

> pollution monitor looks like, they cost hundreds

> of thousands to buy and tens/hundreds of thousands

> to run each year ... that's why there are only a

> handful in southwark, because pollution figures

> can be accurately extrapolated from traffic

> volumes.

[Earl Aelfheah]

Spartacus Wrote:

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> But to follow up on penguins point

>

> They can't tell what sort of engine the vehicle is

> using

> If 100 hybrids or electric go over it on battery

> power for example, it still counts then as cars

> and therefore the calculated figures will be

> inaccurate.

>

> Therefore "guestimated" figures based solely on

> volume not engine type are at best misleading at

> wirst just completely wrong.

You can use data on the proportion of hybrid, electric, diesel and petrol vehicles registered and combine with counts and weights of traffic, as well as flow data to get a pretty accurate idea of pollution levels. This is what they mean by ?modelling?. You can see the methodology in the report, published on Soutgwarks website. It?s not perfect, but as long as you apply the same methods consistently over time, you get a good idea of trend.

As we have seen with the traffic monitoring data however, if it doesn?t show what people already believe to be the case, many will dismiss it.

As a reminder, traffic counts show traffic across all monitoring sites down by 12% and cycling up by 61%.

[Earl Aelfheah]

Btw, I just noticed that Rockets claimed the traffic count data published was ?modelled? and not based on actual vehicle counts. That?s not true.

[heartblock]

Btw, the data for pollution was modelled and traffic counts for ED Grove Central pre- LTN was modelled data.

"A model set-up for 2019 was modified to include traffic and emissions data for 2021 (based on June 2021 traffic data), to provide an estimate of the current air quality impact of the scheme. The model set-up was based on recent modelling for LTN assessments in the neighbouring borough of Lambeth. Due to project timescales, the model set-up was not verified against local monitoring, however comparison against monitoring data will follow, in order to inform the uncertainty in the conclusions of the assessment" From Dulwich Streetspace report.

This figure 14214 for ED Central Sept 19 is 'modelled' on a measure taken 8 months earlier in Jan 19 and the Council says this ATC is new for 2021 - the data point measure from the actual ATC only has one measure in Sept 2021, so it is a mystery how a non-existent ATC even measured Jan 19 traffic count of 11832 - 2382 vehicles a day added to a dubious count. Also why are they using Sept 2021? This was during the fuel crisis when driving patterns were abnormal.

Where is the ED Grove peak time pollution data?

[Rockets]

rahrahrah Wrote:

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

> Btw, I just noticed that Rockets claimed the

> traffic count data published was ?modelled? and

> not based on actual vehicle counts. That?s not

> true.

Rahx3 - sorry, you're wrong - it is very much true.

Take a look at the monitoring report and methodology, it's there in black and white - the EDG Central "reduction" numbers are modelled.

Here's a question for you - you claim traffic is down by 12% on all monitoring sites. Given Southwark-wide traffic is down by at least 7% as a result of the pandemic and that 7% has not been modelled into the council's report do you think that 12% figure can legitimately be claimed to be as a result of the LTNs?

In fact, I bet if you factor in the 7% pandemic reduction in traffic and then remove the modelled data for EDG Central (which alleges a drop of around 3,000 vehicles) then you'll be getting very close to either no change or an increase in comparative overall traffic. Any thoughts on that?

[Earl Aelfheah]

All raw traffic data files are available for download via Southwark maps. Select ?Southwark Highways? as the map configuration and then select ?traffic counts?. https://geo.southwark.gov.uk/connect/analyst/mobile/#/main

This tells you where, when and how data was collected: https://www.southwark.gov.uk/assets/attach/77419/FAQ-and-data-collection-methodology_Dulwich-Streetspace_Sept-2021.pdf

[heartblock]

Well done Rahx3 for reposting exactly what I posted before - as you can see the ED Grove Central ATC has 4 counts on the 6th, 13th, 20th and 27th Sept 2021 and none in the period from 2016 up until those counts. As I said a new ATC from 2021, so the pre-LTN data is modelled.

[heartblock]

Now let's look at 2019 data from the one ATC that was recording in 2019 - EDG -6 combining East and West traffic this counter recorded 8961. This is a REAL count.

So if we minus this REAL count in 2019 from the 2021 REAL count - we have 13681 - 8961, that is 4760 more vehicles a day an increase of around 35%.

[Rockets]

But Heartblock...never let the truth get in the way of a good story hey...it amazes me when some on the pro-side post things that just validate what we are saying - perhaps they are actually double-agents.....

Rahx3 - any response to my question on the 7% area wide reduction...or is that another case of not letting the truth get in the way of a good story too.......?

[Earl Aelfheah]

heartblock Wrote:

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

> Well done Rahx3 for reposting exactly what I

> posted before - as you can see the ED Grove

> Central ATC has 4 counts on the 6th, 13th, 20th

> and 27th Sept 2021 and none in the period from

> 2016 up until those counts. As I said a new ATC

> from 2021, so the pre-LTN data is modelled.

It has a count in 2019. It also has counts for East and West and turning data. So it has accurate data for that section both before and after the implementation of the LTN. I suggest that anyone interested in the data simply looks for themselves.

[Earl Aelfheah]

BTW - Lime (electric hire bikes), have again extended their operating area so people can now hop on one for Herne Hill Station from ED to connect with the Thames link.

[Earl Aelfheah]

If we could get a segregated bike Lane on EDG / Half Moon Lane, it would be much easier for people to connect to Henre Hill and onwards via the Railton LTN to Brixton tube with grab and go electric bike.

[alice]

At 15p a minute it?d be cheaper to get a cab.

[Bicknell]

rahrahrah Wrote:

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

> If we could get a segregated bike Lane on EDG /

> Half Moon Lane, it would be much easier for people

> to connect to Henre Hill and onwards via the

> Railton LTN to Brixton tube with grab and go

> electric bike.

not sure theres room on these routes without delaying the buses even more

[Waseley]

Edited - wrong thread

[heartblock]

"It has a count in 2019. It also has counts for East and West and turning data. So it has accurate data for that section both before and after the implementation of the LTN. I suggest that anyone interested in the data simply looks for themselves."

Nope 4 counts and all from 2021 - I'm afraid you are either looking at the wrong ATC or are relying on the table that Southwark published. The ED Grove Central outside of the Heart Centre has data as below and no other.

ID :

ROAD : East Dulwich Grove

ORIGINAL_REF : 4684-LON

DIRECTION :

MONTH : 0

YEAR : 0

TOTAL_FLOW :

PEDAL_MOTORCYCLE :

CAR :

TRAILER_CARAVAN_VAN :

_2AXLE_TRUCKorBUS :

_3AXLE_TRUCKorBUS :

_4AXLE_TRUCK :

LGV :

TOTAL_LARGER_THAN_CAR : 0

DFT_PEDAL_CYCLE :

AVERAGE_SPEED :

_85TH_SPEED : 0

LINK_RAW_DATA_Globalshare : Click to open

MONITORING_TYPE :

EASTING : 533522

NORTHING : 175083

Start_Date : 2021-09-06

Zoom to record on map

ID :

ROAD : East Dulwich Grove

ORIGINAL_REF : 4684-LON

DIRECTION :

MONTH : 0

YEAR : 0

TOTAL_FLOW :

PEDAL_MOTORCYCLE :

CAR :

TRAILER_CARAVAN_VAN :

_2AXLE_TRUCKorBUS :

_3AXLE_TRUCKorBUS :

_4AXLE_TRUCK :

LGV :

TOTAL_LARGER_THAN_CAR : 0

DFT_PEDAL_CYCLE :

AVERAGE_SPEED :

_85TH_SPEED : 0

LINK_RAW_DATA_Globalshare : Click to open

MONITORING_TYPE :

EASTING : 533522

NORTHING : 175083

Start_Date : 2021-09-13

Zoom to record on map

ID :

ROAD : East Dulwich Grove

ORIGINAL_REF : 4684-LON

DIRECTION :

MONTH : 0

YEAR : 0

TOTAL_FLOW :

PEDAL_MOTORCYCLE :

CAR :

TRAILER_CARAVAN_VAN :

_2AXLE_TRUCKorBUS :

_3AXLE_TRUCKorBUS :

_4AXLE_TRUCK :

LGV :

TOTAL_LARGER_THAN_CAR : 0

DFT_PEDAL_CYCLE :

AVERAGE_SPEED :

_85TH_SPEED : 0

LINK_RAW_DATA_Globalshare : Click to open

MONITORING_TYPE :

EASTING : 533522

NORTHING : 175083

Start_Date : 2021-09-20

Zoom to record on map

ID :

ROAD : East Dulwich Grove

ORIGINAL_REF : 4684-LON

DIRECTION :

MONTH : 0

YEAR : 0

TOTAL_FLOW :

PEDAL_MOTORCYCLE :

CAR :

TRAILER_CARAVAN_VAN :

_2AXLE_TRUCKorBUS :

_3AXLE_TRUCKorBUS :

_4AXLE_TRUCK :

LGV :

TOTAL_LARGER_THAN_CAR : 0

DFT_PEDAL_CYCLE :

AVERAGE_SPEED :

_85TH_SPEED : 0

LINK_RAW_DATA_Globalshare : Click to open

MONITORING_TYPE :

EASTING : 533522

NORTHING : 175083

Start_Date : 2021-09-27

[Rockets]

Rahx3 - you're flogging a dead horse and you are wrong. It doesn't matter how many times you say it you're wrong - the EDG Central numbers are modelled.

You also seem reluctant to address my questions - one wonders why that might be....;-)

Here is is, again, in case you missed it.....

Here's a question for you - you claim traffic is down by 12% on all monitoring sites. Given Southwark-wide traffic is down by at least 7% as a result of the pandemic and that 7% has not been modelled into the council's report do you think that 12% figure can legitimately be claimed to be as a result of the LTNs?

In fact, I bet if you factor in the 7% pandemic reduction in traffic and then remove the modelled data for EDG Central (which alleges a drop of around 3,000 vehicles) then you'll be getting very close to either no change or an increase in comparative overall traffic. Any thoughts on that?

[smooch]

I don't trust any data or any information now that is provided by Southwark Council. Sorry state of affairs.

[dougiefreeman]

I shouldn't think rahrahrah will be on again any time soon now that their post has been exposed for what it is. It does seem to me that their trend is to post fake news at times of relative quietness on this thread presumably in attempt to sway fleeting readers who perhaps skip to the most recent page. Then once the fact-checkers come on and put right the swathes of mis-truths in their posts, rahrahrah disappears again for a while until the opportunity arises again.

I don't recall any attempt ever by rahrahrah to address questions posed by anti-LTNers on this or the other threads - just statement after statement of 'their truth'.

[Rockets]

Dougie it seems to be the modus operandi of many of the pro-LTN supporters on this thread - they don't ever respond to questions, especially those questions based on fact - they deal only in mistruths peddled by the council to support their argument and don't take time to actually analyse the council's data. It seems many are happy to be an organ of the LTN's are awesome propaganda and are happy to prop-up the narrative that LTNs have been a success when it is clear they have been anything but.

[Rockets]

And still no response from Rahx3.....what a surprise!

Speaking of propaganda the latest Streetspace Update dropped through our door today and the council still are touting their "reduction" % for Dulwich with no reference to the fact that it doesn't take any consideration for the area-wide reduction in traffic due to the pandemic.

What is does say, interestingly, is that the council now has a full year of data showing that traffic on main roads is "still below the pre-pandemic level" - but they do not give a % figure. This is very telling as I suspect, given the way the council spins things to their advantage, that traffic on main roads will be only just below the pre-pandemic levels and I bet you that won't include any of the area-wide reduction in traffic so in reality traffic may have increased on the main roads taking the brunt of the displacement.

Has the council shared the figure they tease people with in their Streetspace document?

[legalalien]

I'm slightly confused.

The update says that "The largest overall traffic reduction has been monitored in both the Dulwich (-14%) and Walworth (-18%) areas as of September 2021". and then "In November 2021, we again collected traffic data from nine of the roads surrounding the Dulwich Streetspace scheme. The monitoring showed a further 7% reduction in all motor vehicles compared to pre-scheme levels This is a sustained reduction from monitoring carried out on the same roads in September 2021".

If pre-scheme is 100% of traffic, and September is down to 86%, then is November down a further 7% of the original (so now 79% of pre-scheme), or is it down by a further 7% of the 86% figure, or has it gone up slightly from September so is now 93% of the original figure? Given it says "further" reduction then it must be one of the first two interpretations?

Or is it the case that there's two separate measurements, one of the Dulwich area generally, and one of the nine roads?

I'm also not sure what "overall net traffic" is - what is it "net" of? Is something deducted? Or do they mean aggregate traffic or perhaps average traffic levels?

[goldilocks]

I'm similarly confused @legalalien and also increasingly and continually frustrated by the council's inability to release the underlying data that would make all of this clearer.

The document does say that it is being uploaded to the site, though i not there is no timeframe attached to that comment.