Slapdash signals

I tweeted a little clip of something from a commute of a few months ago. It was the police making a couple of annoying, potentially very dangerous, and entirely understandable mistakes.

First, the police driver has blocked an advance stop box. I imagine probably the lights were green when they entered it, but a traffic jam ahead of them prevented them continuing on their way before the lights turned red.

It’s a common problem. Blocking ASLs is the least of it. Blocking pedestrian crossings and entire junctions happens all the time too, because motorists know they can try their luck and just keep bumper hugging in slow-moving traffic without worrying about whether they’ll be able to see when the lights turn green again. Aggressive motorists can nudge forward through red lights and pedestrian crossings, ready to floor it when they see their light turn green.

My thesis is that this behaviour is not merely accommodated by repeater traffic lights on the far side of junctions, but over time it has been slowly, creepingly encouraged by it. Those who have driven or cycled outside the UK will have noticed that having multiple signal heads to display the same signal strewn about a junction are quite a British peculiarity. They’re not unheard of elsewhere, but it’s far more normal to have just the one signal — in most countries, always situated at the stop line (but in some, always situated directly opposite on the far side of the junction).

And they exist purely to accommodate drivers who have overshot their stop line. I guess at some time, somebody identified that there was a niche problem: occasionally a driver accidentally stopped over the line, or had to make an emergency stop for some reason, and then couldn’t see when lights changed. And they invented far-side repeaters as a solution, and in doing so have created a far more ubiquitous and pernicious problem.

But this isn’t the only danger created by far side repeater signals. The second, equally excellently demonstrated by the police in the original video, is that they turn junctions with the slightest complexities into a dangerously confusing mess. The police driver clearly sits in the advanced stop box watching a signal on the far side of the junction, and shoots off when they see it turn green. Only to realise that they’ve been watching one of the many independent signal heads that is associated with an entirely different stop line in the junction complex. Luckily on this occasion there wasn’t anybody in the pedestrian crossing, and they correct their mistake before hitting the traffic that actually has the green light.

Far side repeaters have also created ample opportunity for the opposite kind of confusion: people who are making a turn will ignore any red light in the street they’re turning into, because they’ve been trained to assume that such lights must be far side repeaters aimed at traffic waiting in the perpendicular arm of the junction. So we get people who are making turns shooting through pedestrian crossings because they’ve been trained that when you’re moving through a junction, it’s normal to see red lights that don’t apply to your flow and which you can safely ignore.

This is just one specific, but excellently illustrative example of two more fundamental flaws in how we design and manage our streets:

  1. The motoring industry has successfully defined “road safety” as being accommodating the bad behaviour of motorists and making sure that the dangerous situations they create don’t end up with them killing themselves, rather than about preventing them creating those dangerous situations.
  2. We have lots of lengthy and precise regulations and design guidance which get prescriptive about lots of detail that isn’t really very important (giving councils plenty of opportunity to say improvements are impossible because the technical guides say no) while remaining silent on lots of big stuff that has a massive effect on the usability of our streets, allowing councils to create all kinds of confusing slapdash rubbish.

This latter point is perhaps more perfectly illustrated by this deadly pedestrian crossing in Sheffield, which last I checked had not been fixed because it follows the strict and detailed regulations and design guidance perfectly, while being utterly and fatally incomprehensible to everyone who has to use it.

Anyway. That’s my pitch. The campaign to ban far side repeater lights is open.



5 thoughts on “Slapdash signals”

  1. I like the traffic lights in some French villages where they are situated on a narrow part of the road (no junction involved) and are triggered to turn red only when a motorist is detected to be over the speed limit. Never a problem on a bike!

  2. Where far-side repeaters should be reinstated urgently is on pedestrian crossings. The new waist-level signals are hopeless, invisible when there are many pedestrians waiting to cross, and as illustrated so well in your clip from Sheffield, ambiguous.

  3. Australian guides acknowledge the confusion that can occur from too many visible lamps, but contrast that with the need to provide a clear indication if a lamp fails. For most intersections the choice is 3 facings for each direction/movement/approach.

  4. Poor placement of traffic lights is also, I conjecture, responsible for many cars stopping over the stop line and on thef ASLs.

    Whilst the latter are a terrible design, it would be nice if motorists weren’t encouraged to stop in them because of where the lights become visible.

  5. The use is ubiquitous in Australia too and similar issues exist except where the ASL has bike detectors and a dedicated bike signal. Drivers learn not to stop or creep into the bike area because they have to wait longer as the bike signal activates. Also, turn lights are arrows and are much larger than the bike signals.

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