Traffic Light Sequencing on the A725 northbound and southbound: FOI release

Information requested

Please provide details of the traffic light sequencing for the traffic lights on the A725 northbound and southbound, close to the junctions with Kirkshaws Road and Hagmill Road, Coatbridge on 15 February 2025 from 20:10 – 20:20

Response

While our aim is to provide information whenever possible, in this instance Transport Scotland does not have the information you have requested. Transport Scotland does not have this information because the junction at the above location is controlled by intelligent traffic signals, Microprocessor OptimisedVehicle Actuation, (MOVA) that do not follow a set sequence, but alter depending on traffic flow approaching the location, but adjust dynamically depending on traffic flow approaching the location. A more detailed explanation is provided later in this response. A more detailed explanation is provided later in this response.

This exemption is not subject to the 'public interest test', so we are not required to consider if the public interest in disclosing the information outweighs the public interest in applying the exemption

Transport Scotland's contractor Scottish Roads Partnership, (SRP) is responsible for the above project and for the operation and maintenance of the A725 between Bothwell Bridge and Shawhead Junction. This includes the area you refer to, which is the A725 at the crossroads junction with Kirkshaws Road and Hagmill Road. Please refer to the Transport Scotland website for a map of SRP’s trunk road network: Project details | Overview | Transport Scotland

The MOVA system is variable depending on the traffic flows its sensors detect approaching the junction. It may be helpful to explain that MOVA has two modes of operation depending on the road conditions – these are congested and uncongested (free-flowing). In free-flowing mode, the aim of MOVA is to disperse any queues which have built up on a red signal, it then assesses the traffic flows approaching on each arm of the junction and calculates if extending the current green light time would be beneficial. If it is beneficial, then the current green light time is extended and the calculation is repeated. This continues until there is no benefit in extending the green light time and the signals move to the next stage.

When the network is congested, MOVA operates in a capacity maximising mode. This assesses which approaches are overloaded and how efficiently the green light time is being used and seeks to determine a set of signal timings which will maximise the throughput of the junction under the current conditions. Shawhead Junction (North, Central & South) is automatically controlled by three sets of intelligent traffic signal systems, microprocessor optimised vehicle actuation (MOVA), that are synchronised with each other. It should be noted that MOVA has no function which would allow the control of driver behaviour.

Attached as Annex A, is a copy of a traffic signal sequence diagram for the A725 at Kirkshaws Road and Hagmill Road and reiterate that the traffic light sequencing is not fixed but variable, depending on the traffic flows its sensors detect approaching the junction.

For further information, you can read more about how this technology works in SRP's leaflet: https://www.transport.gov.scot/media/45763/leaflet-autumn-2019-shawhead-m8-m73-m74.pdf 

SRP monitor these locations regularly to ensure they continue to operate safely and efficiently and if you require any further information, SRP has set up a dedicated enquiry line for the project. SRP can be contacted on 0800 042 0188, or by email – info@scotroadspartnership.co.uk

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FOI - 202500486707 - Information released - Annex A

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