Delays Caused By Sequencing of Lights

Updates

• Thank you for your report concerning traffic lights at Junction 3 of the M3.

  In response to your query, it is important to appreciate the basic operational method of both junctions on the roundabout. Furthermore, the standalone pedestrian crossing across the A322 from Lightwater, belongs to Surrey County Council and not National Highways.

  The current status of the roundabout operates under a planned programme known as MOVA – Microprocessor – Optimised – Vehicle - Actuation. The nature of MOVA is dynamic, varying the cycle time based on saturation and occupancy as detected by diamond-shaped detector loops in the road. When cruise speed gaps are detected, priority is then given to the next stage in the cycle. Being dynamic, the green times vary according to these factors. Due to the nature of HGVs, which struggle with slow take-off, this unfortunately could result in a “false gap” where all of a sudden, the phase loses right of way, and this is very typical of HGVs travelling from Lightwater towards Bracknell on the A322, as you may have experienced. This, however, is difficult to predict as no two traffic cycles are the same.

  As mentioned in your report, it is possible and predictable to release the southbound off-slip around the circulatory to the other side where the northbound off-slip is at green as well. Hence, the vehicles moving around towards Bracknell will be running into a red for a few more seconds before getting the green again.

  There is a fault with one of the detectors on the southbound side, however this will not impact the operation, as its role is to detect vehicles crossing in the middle from the centre island to the roundabout.

  For future improvements, we are looking into making some minor changes to the tools within the each controller which could improve the south-to-north linking and through-put, however this is only a minor change and will require validation on site before any benefits are realised. A study has been carried out to look at a package of improvements, however these will be major works dependent on funding in future years.

  Thank you once again for taking the effort to write to us.

  If you require any further update on this issue our Customer Contact Centre is available 24 hours a day at:

  • 0300 123 5000

  • info@highwaysengland.co.uk

  Kind regards

  National Highways

  Posted by at 14:17, Mon 20 June 2022