What causes traffic light faliures? M25 J28

[qwertyK]

Close to once a month I'd say the traffic lights at the Brook Street Roundabout (M25 J28) here https://maps.app.goo.gl/nDT9XrrrACoSL1v28 fail. Today being the most recent example. https://www.echo-news.co.uk/news/242888 ... l-failure/

What causes traffic lights this to fail so often, I've never seen it happen so often anywhere else? Surely someone at National Highways must be like, hey, maybe we need to replace them. They're building the new junction roads but the actual roundabout itself is in a terrible state. Potholes, no road markings, traffic light faliures.

[traffic-light-man]

The possibilities are numerous. There are various fault conditions where the specified fail state is to extinguish the lamps, and then there are also conditions within the configuration that may also cause them to extinguish lamps depending on how that's been written (i.e. designer's/authority's choice).

Those signals aren't all that old given the type of equipment, however they are from a defunct manufacturer, so support on those is getting scarce which may play into matters if there is indeed a problem with the equipment itself.

There is also the possibility of poor mains electricity, which wouldn't really be a true signals fault but would of course cause the signals to fail.

[RichardA35]

Close to once a month I'd say the traffic lights at the Brook Street Roundabout (M25 J28) here https://maps.app.goo.gl/nDT9XrrrACoSL1v28 fail. Today being the most recent example. https://www.echo-news.co.uk/news/242888 ... l-failure/

What causes traffic lights this to fail so often, I've never seen it happen so often anywhere else? Surely someone at National Highways must be like, hey, maybe we need to replace them. They're building the new junction roads but the actual roundabout itself is in a terrible state. Potholes, no road markings, traffic light faliures.

Given the new loop road being constructed at the junction, the traffic patterns through the signals will change after this is opened and there is provision to reduce the lanes at the N/B off slip stop line from 4 to 3 lanes. My guess is that we will see the current maintenance regime continuing and any major replacement needed would coincide with the loop road opening.