Publication - FOI/EIR release

A725 traffic light sequencing information: EIR release

Published: 10 October 2024
Topic: Public sector, Transport
FOI reference: EIR/202400431645
Date received: 11 September 2024
Date responded: 26 September 2024

Information request and response under the Environmental Information (Scotland) Regulations 2004

Information requested

Information relating to the traffic lights located at the junction of the A725 (North Road) and the A8.

1. Information including sight of any written or electronic communication detailing the sequence and timings between traffic light changes that would have been in operation on 5 May 2023.

2. Information including sight of any written or electronic communication detailing any changes to the traffic light sequence that have occurred since 10 October 2017.

3. Please provide any photographs held relating to the above requested information.

Response

As the information you have requested is 'environmental information' for the purposes of the Environmental Information (Scotland) Regulations 2004 (EIRs), we are required to deal with your request under those Regulations. We are applying the exemption at section 39(2) of the Freedom of Information (Scotland) Act 2002 (FOISA), so that we do not also have to deal with your request under FOISA.

This exemption is subject to the 'public interest test'. Therefore, taking account of all the circumstances of this case, we have considered if the public interest in disclosing the information outweighs the public interest in applying the exemption. We have found that, on balance, the public interest lies in favour of upholding the exemption, because there is no public interest in dealing with the same request under two different regimes. This is essentially a technical point and has no material effect on the outcome of your request.

1. Scottish Roads Partnership (SRP), the project contractor for the M8 M73 M74 Motorway Improvement Project, on behalf of Transport Scotland, is responsible for the traffic signals at the A725 Shawhead South Junction mentioned above. SRP’s operations and maintenance team Amey monitored the traffic lights at this location and confirm that the timings are controlled by a system called Microprocessor Optimised Vehicle Actuation (MOVA), which determines the amount of green light time to give to a particular direction. A more detailed explanation is provided below.

In view of this, SRP are unable to determine the exact sequencing and timings of the traffic signals on 5 May 2023 as requested, as 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.

SRP has provided two traffic signal staging diagrams, which I have attached to Annex A and B to this response, that outline the sequencing of these traffic signals. An exception under regulation 11(2) of the EIRs (personal information) applies to some of this information requested because it is personal data of a third party and disclosing it would contravene the data protection principles in Article 5(1) of the General Data Protection Regulation and in section 34(1) of the Data Protection Act 2018. This exception 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 exception.

Under the terms of the exception at regulation 10(4)(a) of the EIRs (information not held), Transport Scotland is not required to provide information which it does not have. We do not have the information you have requested because neither Transport Scotland nor SRP hold communications regarding changes to the traffic light sequencing on 5 May 2023.

This exception is subject to the 'public interest test'. Therefore, taking account of all the circumstances of this case, we have considered if the public interest in disclosing the information outweighs the public interest in applying the exception. We have found that, on balance, the public interest lies in favour of upholding the exception. While we recognise that there may be some public interest in information about communications related to traffic light sequencing, clearly we cannot provide information which we do not hold.

2. It should be noted that on 28 November 2019, as the result of an RTC, the control boxes for the traffic light signals at this location were destroyed after a car strike. Temporary traffic signals were installed for several weeks until new control boxes were manufactured and installed on 12 December 2019. For more information on this please see the link below to our website where you can view this information in the Latest News section: https://www.m8dbfo.co.uk/latest-news/a725-shawhead-at-north-road-junction-good-news/

Other than the above replacement control boxes on 12 December 2019, there has been no changes to the traffic signal sequencing here since 10 October 2017.

As far as SRP are aware the sequencing has been working effectively under MOVA since its installation in October 2017.

I have enclosed the most recent inspection report regarding the traffic signals at Annex C to this request along with previous FOI responses at Annex D which you may be interested in. An exception under regulation 11(2) of the EIRs (personal information) applies to some of the information requested because it is personal data of a third party and disclosing it would contravene the data protection principles in Article 5(1) of the General Data Protection Regulation and in section 34(1) of the Data Protection Act 2018. This exception 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 exception.

I can advise that SRP also undertakes an annual review of the injury accident statistics for its project roads, which include the A8 and A725 at Shawhead Junction. SRP would like to reassure you that they monitor these locations regularly to ensure they continue to operate safely and efficiently and should there be an adverse collision/incident history we would review this area further.

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

3. Under the terms of the exception at regulation 10(4)(a) of the EIRs (information not held), Transport Scotland is not required to provide information which it does not have. We do not have the information you have requested because neither Transport Scotland nor SRP hold photographs in relation to the traffic light sequencing for the location and date range requested.

This exception is subject to the 'public interest test'. Therefore, taking account of all the circumstances of this case, we have considered if the public interest in disclosing the information outweighs the public interest in applying the exception. We have found that, on balance, the public interest lies in favour of upholding the exception. While we recognise that there may be some public interest in information about traffic light sequencing, clearly we cannot provide information which we do not hold.

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