Freedom of Information request - Traffic flow and congestion data from any traffic lights enabled with SCOOT
Request ID: FOI-3868-2324 Date published: 16 February 2024
You asked
Dear 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 2022 to present:
Streatham High Road by Becmead Avenue
Streatham High Road by Prentis Road
Streatham Common North by Valley Road
Streatham Common North by Leigham Court Road
Yours faithfully,
We answered
TfL Refs: FOI-3868-2324; FOI-3869-2324
Thank you for your requests received by Transport for London (TfL) on26 January 2024 asking for SCOOT data for Leigham Court Road, Streatham High Road and Streatham Common North.
Your requests have been considered in accordance with the requirements of the Freedom of Information Act and our information access policy. I can confirm that we hold the information you require. Please see the requested information in the file attached. The closest SCOOT nodes to the junctions listed have been chosen and the below list allows you to identify which have been used for each junction.
Streatham High Road by Becmead Avenue - N09/148a and N09/146u1 Streatham High Road by Prentis Road - N09/146t1 Streatham Common North by Valley Road – N09/165b (closest near Minehead Road) Streatham Common North by Leigham Court Road - N09/181a
Leigham Court Road by Dunravem School - N09/167a Leigham Court Road by Valley Road - N09/167q Please see the below explanation of what each column refers to in the file attached:
SCOOTLink - refers to the SCOOT Link ID.
Location – a brief description of the Location of the Junction typically by road name.
LDES – a brief description of the location of the Link typically by road name.
Latitude
Longitude
Date
VehicleFlowTotal – the total flow observed within a 24 hour period across all links approaching the junction.
FlowDataCompletenessPercentage –the availability of data; 100% is a complete dataset.
AverageCongestionPercentage –the average congestion within a 24 hour period across all links approaching the junction.
CongestionDataCompletenessPercentage – the availability of data; 100% is a complete dataset.
Please note SCOOT Flow may differ to flow data from other validated counts, as the SCOOT system utilises loop occupancy as its primary source of data. This data 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 sited at a distance from the junction where this is minimised, but sometime especially when junctions are close together this issue is exaggerated. Therefore SCOOT Flow should be used more to generalise trend of demands and not actual counts.
SCOOT congestion is defined as the number of consecutive congested intervals in a cycle. It is expressed as a proportion of the cycle time. (A congested interval is fully defined as: An interval where any detector on the link has a full interval (detector operated continuously over the four-second interval) and the back of queue is greater than half the maximum or, alternatively, where more than one detector has a full interval.)
If this is not the information you are looking for, or if you are unable to access it for any reason, please do not hesitate to contact me.
Please see the attached information sheet for details of your right to appeal as well as information on copyright and what to do if you would like to re-use any of the information we have disclosed.
Yours sincerely,
Mary Abidakun FOI Case Officer FOI Case Management Team General Counsel Transport for London
