Brixton Liveable Neighbourhood and LTN schemes - improvements for pedestrians and cyclists

[Brian Taylor]

What's the source for the traffic light data?

It was released in a FOI to TfL.

SCOOT Data Request for Lambeth - a Freedom of Information request to Transport for London

In accordance with the Freedom of Information Act (2000), can you please provide traffic flow and congestion data from any traffic lights enabled with SCOOT (Split Cycle Offset Optimisation Technique), from the following sites in the London Borough of Lambeth since January 2018 to present...

www.whatdotheyknow.com

It's the raw data for Lambeths traffic light sensor data (SCOOT) from 2018 till early 2021.

 

[teuchter]

It was released in a FOI to TfL.

SCOOT Data Request for Lambeth - a Freedom of Information request to Transport for London

In accordance with the Freedom of Information Act (2000), can you please provide traffic flow and congestion data from any traffic lights enabled with SCOOT (Split Cycle Offset Optimisation Technique), from the following sites in the London Borough of Lambeth since January 2018 to present...

www.whatdotheyknow.com

It's the raw data for Lambeths traffic light sensor data (SCOOT) from 2018 till early 2021.

I see, thank you.

I don't have the knowledge or database skills to analyse it, but I would like it to be incorporated into Lambeth's monitoring if possible.

What does it say for the other periphery roads, for example Effra Rd / Dulwich Rd / Milkwood Rd?

 

[Brian Taylor]

I see, thank you.

I don't have the knowledge or database skills to analyse it, but I would like it to be incorporated into Lambeth's monitoring if possible.

What does it say for the other periphery roads, for example Effra Rd / Dulwich Rd / Milkwood Rd?

I'm a software developer and I've done a fair amount of work with databases over the last 4 decades.

I've mapped the Lambeth and TfL data onto google maps

Railton

Railton LTN - Lambeth Data and TfL/SCOOT Traffic Light Data week starting 21/09/2020 – Google My Maps

% changes are against the same week in 2019 (23/09/2019) with the COVID adjustment used by Lambeth Council (93.59%)

www.google.com

Ferndale

Ferndale LTN - 19 to 25-10-2002 compared to same week 2019 – Google My Maps

Lambeth Councils LTN assessment data and TfLs SCOOT data released in an F.O.I. Lambeths date ranges and COVID weighting applied to get the % differences.

www.google.com

Tulse Hill

Tulse Hill LTN - Lambeth Data and TfL/SCOOT Traffic Light Data week starting 29/10/2020 – Google My Maps

% changes are against the same week in 2019 (31/10/2019) with the COVID adjustment used by Lambeth Council (89.21%)

www.google.com

Oval

Oval LTN - Lambeth & TfL Data – Google My Maps

% changes are against the same month in 2019 (December) with the COVID adjustment used by Lambeth Council (76.53%)

www.google.com

The obvious caveats apply - no one else other than me has checked the work as it was done for my own amusement when the data was released
So if you see anything that looks wildly wrong or doesn't work let me know

 

[sleaterkinney]

What's the source for the traffic light data?

WhatsApp.

 

[teuchter]

I'm a software developer and I've done a fair amount of work with databases over the last 4 decades.

I've mapped the Lambeth and TfL data onto google maps

Railton

Railton LTN - Lambeth Data and TfL/SCOOT Traffic Light Data week starting 21/09/2020 – Google My Maps

% changes are against the same week in 2019 (23/09/2019) with the COVID adjustment used by Lambeth Council (93.59%)

www.google.com

Ferndale

Ferndale LTN - 19 to 25-10-2002 compared to same week 2019 – Google My Maps

Lambeth Councils LTN assessment data and TfLs SCOOT data released in an F.O.I. Lambeths date ranges and COVID weighting applied to get the % differences.

www.google.com

Tulse Hill

Tulse Hill LTN - Lambeth Data and TfL/SCOOT Traffic Light Data week starting 29/10/2020 – Google My Maps

% changes are against the same week in 2019 (31/10/2019) with the COVID adjustment used by Lambeth Council (89.21%)

www.google.com

Oval

Oval LTN - Lambeth & TfL Data – Google My Maps

% changes are against the same month in 2019 (December) with the COVID adjustment used by Lambeth Council (76.53%)

www.google.com

The obvious caveats apply - no one else other than me has checked the work as it was done for my own amusement when the data was released
So if you see anything that looks wildly wrong or doesn't work let me know

Thank you; these are interesting to look at.

One thing I notice; there seems to be quite a big variation in the traffic light data between different dates. So for example if I compare the same sites between your Railton map and the Ferndale one, which seem to be based on sampling weeks about a month apart. The Branksome Rd junction is +11% on one and -15% on the other.

Or, Villa Rd/Brixton Rd: +43% on the Railton map (September 2020), +51% on the Ferndale map (October) and then -22% on the Oval map (December).

I assume similar variations would be seen in traffic counts.

 

[edcraw]

I'm a software developer and I've done a fair amount of work with databases over the last 4 decades.

I've mapped the Lambeth and TfL data onto google maps

Railton

Railton LTN - Lambeth Data and TfL/SCOOT Traffic Light Data week starting 21/09/2020 – Google My Maps

% changes are against the same week in 2019 (23/09/2019) with the COVID adjustment used by Lambeth Council (93.59%)

www.google.com

Ferndale

Ferndale LTN - 19 to 25-10-2002 compared to same week 2019 – Google My Maps

Lambeth Councils LTN assessment data and TfLs SCOOT data released in an F.O.I. Lambeths date ranges and COVID weighting applied to get the % differences.

www.google.com

Tulse Hill

Tulse Hill LTN - Lambeth Data and TfL/SCOOT Traffic Light Data week starting 29/10/2020 – Google My Maps

% changes are against the same week in 2019 (31/10/2019) with the COVID adjustment used by Lambeth Council (89.21%)

www.google.com

Oval

Oval LTN - Lambeth & TfL Data – Google My Maps

% changes are against the same month in 2019 (December) with the COVID adjustment used by Lambeth Council (76.53%)

www.google.com

The obvious caveats apply - no one else other than me has checked the work as it was done for my own amusement when the data was released
So if you see anything that looks wildly wrong or doesn't work let me know

Impressive!

 

[sleaterkinney]

I'm a software developer and I've done a fair amount of work with databases over the last 4 decades.

I've mapped the Lambeth and TfL data onto google maps

Railton

Railton LTN - Lambeth Data and TfL/SCOOT Traffic Light Data week starting 21/09/2020 – Google My Maps

% changes are against the same week in 2019 (23/09/2019) with the COVID adjustment used by Lambeth Council (93.59%)

www.google.com

Ferndale

Ferndale LTN - 19 to 25-10-2002 compared to same week 2019 – Google My Maps

Lambeth Councils LTN assessment data and TfLs SCOOT data released in an F.O.I. Lambeths date ranges and COVID weighting applied to get the % differences.

www.google.com

Tulse Hill

Tulse Hill LTN - Lambeth Data and TfL/SCOOT Traffic Light Data week starting 29/10/2020 – Google My Maps

% changes are against the same week in 2019 (31/10/2019) with the COVID adjustment used by Lambeth Council (89.21%)

www.google.com

Oval

Oval LTN - Lambeth & TfL Data – Google My Maps

% changes are against the same month in 2019 (December) with the COVID adjustment used by Lambeth Council (76.53%)

www.google.com

The obvious caveats apply - no one else other than me has checked the work as it was done for my own amusement when the data was released
So if you see anything that looks wildly wrong or doesn't work let me know

Also, the tfl data measures flow, and only works where there are actual traffic lights.

 

[Rushy]

I'm a software developer and I've done a fair amount of work with databases over the last 4 decades.

I've mapped the Lambeth and TfL data onto google maps

Railton

Railton LTN - Lambeth Data and TfL/SCOOT Traffic Light Data week starting 21/09/2020 – Google My Maps

% changes are against the same week in 2019 (23/09/2019) with the COVID adjustment used by Lambeth Council (93.59%)

www.google.com

Ferndale

Ferndale LTN - 19 to 25-10-2002 compared to same week 2019 – Google My Maps

Lambeth Councils LTN assessment data and TfLs SCOOT data released in an F.O.I. Lambeths date ranges and COVID weighting applied to get the % differences.

www.google.com

Tulse Hill

Tulse Hill LTN - Lambeth Data and TfL/SCOOT Traffic Light Data week starting 29/10/2020 – Google My Maps

% changes are against the same week in 2019 (31/10/2019) with the COVID adjustment used by Lambeth Council (89.21%)

www.google.com

Oval

Oval LTN - Lambeth & TfL Data – Google My Maps

% changes are against the same month in 2019 (December) with the COVID adjustment used by Lambeth Council (76.53%)

www.google.com

The obvious caveats apply - no one else other than me has checked the work as it was done for my own amusement when the data was released
So if you see anything that looks wildly wrong or doesn't work let me know

Is the traffic light at the junction of St Matthews Road and Effra Road not scoot enabled? What's the camera symbol at that junction mean? Often seems to be a tailback there up towards Sainburys on Tulse Hill. Sometimes due to northbound traffic congestion on the gyratory. But also sometimes just due to phasing, with no congestion beyond the lights.

What's your take on the data you have processed?

Brixton Hill and Effra Road were catastrophically busy last week and deserted this. It’s very odd.

Last week I counted at least fifteen cars backed up on Kellett Road trying to get onto Effra Road. Not a chance of turning into Kellett Road. Everything was being held up by northbound Brixton Road traffic backing around the gyratory. Southbound traffic heading for Brixton Hill also held up because the tailback blocks the single lane junction between Effra Road and St Matthews Road. This makes Effra Road northbound back up all the way to Sainsburys too. Mayhem.

 

[Brian Taylor]

Thank you; these are interesting to look at.

One thing I notice; there seems to be quite a big variation in the traffic light data between different dates. So for example if I compare the same sites between your Railton map and the Ferndale one, which seem to be based on sampling weeks about a month apart. The Branksome Rd junction is +11% on one and -15% on the other.

Or, Villa Rd/Brixton Rd: +43% on the Railton map (September 2020), +51% on the Ferndale map (October) and then -22% on the Oval map (December).

I assume similar variations would be seen in traffic counts.

It's probably a mix of the variations in traffic, as you said, and the fact that Lambeth have used different weighting from LTN to LTN and week to week.

Railton week of the 21 September - 93.59%
Ferndale week of the 19th October - 78.02%
Tulse Hill week of the 29th October - 89.21%
Oval month of December - 76.53%

There are a few inconsistencies within the Lambeth data that make you wonder how closely it was checked
In the Oval one
Site 2: Meadow Road - North uses a weighting of 99.55% and Site 4: Meadow Road South uses 75.21%.
Site 11: Stockwell Park Road uses 96.47%
Ferndale is pretty consistent as is Tulse Hill.
Railton has a couple of strange ones, Site 8: Railton Road (Daily Flows) at 86.57% and Site 9: Regent Road (Daily Flows) at 86.5%
and the table of data for Site 17: Coldharbour Lane (Daily Flows) is scramble and repeats the PreCovid numbers as the Baseline.

it's difficult to know why neighbouring areas vary in weighting within a relatively short period of time, let alone 2 halves of one street (Meadow Road).

I've tried to use the averages for each LTN and week as above.

 

[Brian Taylor]

Also, the tfl data measures flow, and only works where there are actual traffic lights.

Traffic lights tend to be on roads that have a high enough volume of traffic to justify the need.
There aren't (m)any traffic lights within the LTN zones as the traffic was never high enough to require them.

That's probably why Lambeth didn't use it as it only measures the flow of motor vehicles at traffic lights and their focus is within the LTNs and also on bicycles.

 

[Brian Taylor]

Is the traffic light at the junction of St Matthews Road and Effra Road not scoot enabled? What's the camera symbol at that junction mean? Often seems to be a tailback there up towards Sainburys on Tulse Hill. Sometimes due to northbound traffic congestion on the gyratory. But also sometimes just due to phasing, with no congestion beyond the lights.

What's your take on the data you have processed?


Last week I counted at least fifteen cars backed up on Kellett Road trying to get onto Effra Road. Not a chance of turning into Kellett Road. Everything was being held up by northbound Brixton Road traffic backing around the gyratory. Southbound traffic heading for Brixton Hill also held up because the tailback blocks the single lane junction between Effra Road and St Matthews Road. This makes Effra Road northbound back up all the way to Sainsburys too. Mayhem.

I checked the TfL data again, that traffic light isn't in there. Why I don't know. The camera symbol is an LTN barrier according to the map here and I may have misplaced it


What I see, when the TfL data is added to show the areas outside the LTN, seems to back up what most of us have seen when we go out and about. The quieter roads within the LTN are even quieter and the busier roads surrounding them are even busier. Not a surprise really.

 

[snowy_again]

And that is why I assume TfL put a big caveat on using that data for traffic flow monitoring (from the FOI)

“Scoot Flows may differ flow other validated counts as the SCOOT system utilises loop occupancy as it primary source of data, this is then
modelled into a flow count via an average occupancy per vehicle.

This is often sensitive to over or under saturation, e.g. when vehicles are sat
over the detector for long period of time such as in congestion queuing at
the lights. The detectors are often siting at a distance from the junction
where this is minimised but sometime especially when junctions are close
together this issue is exasperated.

Therefore Scoot Flow should be used more to generalise trend of demands and not actual counts.”

 

[sleaterkinney]

Traffic lights tend to be on roads that have a high enough volume of traffic to justify the need.
There aren't (m)any traffic lights within the LTN zones as the traffic was never high enough to require them.

That's probably why Lambeth didn't use it as it only measures the flow of motor vehicles at traffic lights and their focus is within the LTNs and also on bicycles.

Are you trying to prove that Lambeth are wrong?

 

[teuchter]

and the table of data for Site 17: Coldharbour Lane (Daily Flows) is scramble and repeats the PreCovid numbers as the Baseline.

I noticed that too.

I wouldn't say I'm hugely impressed with the reports produced for Lambeth, and see them as "better than nothing". I don't really see why they don't use the traffic light data as well, partly because it seems it provides a continuous record, and as long as it's interpreted properly by people who actually understand what it represents and what its limitations are, that seems an opportunity to average things out and avoid misleading artefacts arising from the particular conditions in a particular week. But I imagine that Lambeth does not have an enormous budget out of which to pay its traffic consultants.

Even though you are coming at this from an anti LTN angle I'm impressed with the maps you've produced. I don't know how easy it is to automate it all but it would certainly be interesting to use them to look at the data week by week, and see how things change over time.

Like I think I've already said, I was a bit surprised by how positive Lambeth's results were, because it would not be abnormal to expect disruption in the months immediately following introduction. For this same reason, the numbers shown in the SCOOT data don't cause me too much concern. What's more important is to look at how things are going 6 and 12 months in.

In any case, it's incredibly difficult right now to untangle LTN effects from everything else that is currently going on.

 

[Brian Taylor]

I noticed that too.

I wouldn't say I'm hugely impressed with the reports produced for Lambeth, and see them as "better than nothing". I don't really see why they don't use the traffic light data as well, partly because it seems it provides a continuous record, and as long as it's interpreted properly by people who actually understand what it represents and what its limitations are, that seems an opportunity to average things out and avoid misleading artefacts arising from the particular conditions in a particular week. But I imagine that Lambeth does not have an enormous budget out of which to pay its traffic consultants.

Even though you are coming at this from an anti LTN angle I'm impressed with the maps you've produced. I don't know how easy it is to automate it all but it would certainly be interesting to use them to look at the data week by week, and see how things change over time.

Like I think I've already said, I was a bit surprised by how positive Lambeth's results were, because it would not be abnormal to expect disruption in the months immediately following introduction. For this same reason, the numbers shown in the SCOOT data don't cause me too much concern. What's more important is to look at how things are going 6 and 12 months in.

In any case, it's incredibly difficult right now to untangle LTN effects from everything else that is currently going on.

I agree with you
Getting the data into the maps isn't too difficult or time consuming, but so far we only have what Lambeth gives us and what we can get out of TfL via FOI requests.

We'll all have to wait and see this plays out over the next few months.

 

[teuchter]

And that is why I assume TfL put a big caveat on using that data for traffic flow monitoring (from the FOI)

“Scoot Flows may differ flow other validated counts as the SCOOT system utilises loop occupancy as it primary source of data, this is then
modelled into a flow count via an average occupancy per vehicle.

This is often sensitive to over or under saturation, e.g. when vehicles are sat
over the detector for long period of time such as in congestion queuing at
the lights. The detectors are often siting at a distance from the junction
where this is minimised but sometime especially when junctions are close
together this issue is exasperated.

Therefore Scoot Flow should be used more to generalise trend of demands and not actual counts.”

It seems fairly legitimate to use it to say that there's more or less traffic at a certain location, when you compare two date ranges. But I'd want to hear that from someone who fully understood what the data represents and what it can and cannot tell us.

 

[edcraw]

Well you seem to think that anti LTN people are right wing supporters.

You take great relish in putting up stuff about the right wing candidate.

So dont come all not lump everyone together at me thankyou.

Too true that anti LTN people aren’t all right wing - Claire fox also hates them.

 

[Gramsci]

Too true that anti LTN people aren’t all right wing - Claire fox also hates them.

Don't quite see what you are getting at. Can you make it clear?

 

[edcraw]

Don't quite see what you are getting at. Can you make it clear?

Isn't it clear? I'm agreeing with your point that people against LTNs aren't all right wing. Claire Fox certainly isn't right wing is she?

 

[CH1]

Isn't it clear? I'm agreeing with your point that people against LTNs aren't all right wing. Claire Fox certainly isn't right wing is she?

I guess she is a fellow traveller with George Galloway.
Anti EU anti Scottish referendum anti Blair etc etc.

But I fear your question is a tortuous self-contradiction from the philosophy school of Frank Furedi.

 

[DJWrongspeed]

I saw a car in our LTN with two number plate covers. Looked quite well made.
Assume they were removed after exiting the area

 

[Rushy]

I checked the TfL data again, that traffic light isn't in there. Why I don't know. The camera symbol is an LTN barrier according to the map here and I may have misplaced it
View attachment 263402View attachment 263402

What I see, when the TfL data is added to show the areas outside the LTN, seems to back up what most of us have seen when we go out and about. The quieter roads within the LTN are even quieter and the busier roads surrounding them are even busier. Not a surprise really.

I think that would be an interesting light to have data for. It is the stretch from that light up to Sainsburys which has become so often congested. Yet Lambeth has said there is a 20% (IIRC) decrease in traffic on that road. It does not look (or sound) that way but it varies tremendously.

Gate 5 on St Matthews Road is is such an afterthought that they don't even bother showing the road on their maps - and not just the map you have appended above. It should be just north of the junction of St Matthews Road with Hicken Road.

 

[edcraw]

I saw a car in our LTN with two number plate covers. Looked quite well made.
Assume they were removed after exiting the area

Yep, seen that a fair bit. You've got to be pretty brave/foolish to do that as the consequences are pretty harsh.

Does rather smack of driver entitlement & selfishness.

 

[Brian Taylor]

I think that would be an interesting light to have data for. It is the stretch from that light up to Sainsburys which has become so often congested. Yet Lambeth has said there is a 20% (IIRC) decrease in traffic on that road. It does not look (or sound) that way but it varies tremendously.

Gate 5 on St Matthews Road is is such an afterthought that they don't even bother showing the road on their maps - and not just the map you have appended above. It should be just north of the junction of St Matthews Road with Hicken Road.

View attachment 263525

I'll fix that. The gates were a best guess based on Lambeths description.

 

[Rushy]

I saw a car in our LTN with two number plate covers. Looked quite well made.
Assume they were removed after exiting the area

On Railton Road (Herne Hill end) motorbikes are driving up onto the pavement and driving through parks to avoid the cameras.

 

[Gramsci]

Isn't it clear? I'm agreeing with your point that people against LTNs aren't all right wing. Claire Fox certainly isn't right wing is she?

Do you think she is right wing?

 

[snowy_again]

I see the failed actor has ‘fewer cycle lanes’ on the front page of his ‘open london’ manifesto!

 

[edcraw]

Do you think she is right wing?

No, that’s my point. I was trying to be helpful to back up your point.

 

[teuchter]

I see the failed actor has ‘fewer cycle lanes’ on the front page of his ‘open london’ manifesto!

The green party has been notably quiet on the LTN issue (or at least that has been my impression) so it's interesting to see LTNs specifically mentioned in their Mayoral manifesto.

 

[sleaterkinney]

Isn't it clear? I'm agreeing with your point that people against LTNs aren't all right wing. Claire Fox certainly isn't right wing is she?

She is Brexit party and was made a peer by Johnson.

There is always the aptly named ukip candidate: