Request ID: FOI-0451-2122 Date published: 22 June 2021
You asked
Hello there
I am not sure if the junction has SCOOT data, but if there is SCOOT data available for the traffic light junction between Croxted Road and Norwood Road, please would you be able to send me the raw data, as far back as it goes?
Thank you very much
We answered
TfL Ref: FOI-0451-2122
Thank you for your request of 4th June 2021 asking for SCOOT data from south east London. Your request has been considered in accordance with the requirements of the Freedom of Information Act and our information access policy.
Specifically you asked:
“I am not sure if the junction has SCOOT data, but if there is SCOOT data available for the traffic light junction between Croxted Road and Norwood Road, please would you be able to send me the raw data, as far back as it goes?
The data is provided in the attached spreadsheet (you may need to expand the width of some columns to read it in full). The following provides an explanation of what each column refers to within the spreadsheet:
SCOOTNodeID – Refers to the SCOOT Junction ID
NodeDescription – A brief description of the location of the Junction typically by road name
Latitude – The position of the junction along the North/South plane
Longitude – The position of the junction along the East/West plane
NumberOfLinks – Refers to the number of SCOOT links which approach the Junction
Date – The date of the data
TwentyFourHourVehicleFlowTotal – The total flow observed within a 24 hour period across all links approaching the junction
FlowDataCompletenessPercentage – Refers to 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 – Refers to the availability of data; 100% is a complete dataset
Please note also that SCOOT Flow data may differ from other validated counts as the SCOOT system utilises loop occupancy as it primary source of data, which 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 sometimes - 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.)
The data provided here is given as recorded and we are not able to validate this data.
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,
David Wells FOI Case Officer FOI Case Management Team General Counsel Transport for London
