Conflicting greens – the implications of a new Oxford junction for ‘simultaneous green’

The Dutch ‘simultaneous green’ junction arrangements allow people walking and cycling to progress through signal controlled junctions in any direction they choose, at the same time as people from all the other arms of the junction.

‘Simultaneous green’ works well on very large junctions, as this David Hembrow video shows –

As well as on smaller ones. My video this time –

In Britain, however, there is some confusion about whether these kinds of arrangements would be legal, particularly as they involve ‘conflicting greens’ – green signals running at the same time on arms of a junction that are an angle to each other. (See this thread on the Cycling Embassy forum, for example).

Now of course we already have examples of ‘conflicting greens’ in the UK – greens for traffic from opposite arms of a junction, which allow people to turn right across the opposing traffic stream. For instance, if I’m turning right in my car, or on my bike, I have a green signal to go, while someone heading straight through the junction from the opposite direction also has a green. We both have a green, yet our paths will cross! The answer is – the turning party yields, rather than assuming green means a manoeuvre can be performed without conflict.

So this seems to be a straightforward objection to the ‘we don’t do conflicting greens in the UK’ claim.

But what about greens from junction arms that are not directly facing each other? What about you having a green to go straight ahead, while the junction to your left – at 90° to your junction – also has a green?

I was told last year by a highway engineer, whose opinion I value, that there isn’t actually anything in UK traffic regulations that specifically rules out doing this. He explained that this option is technically available. You could give motor traffic green signals simultaneously on two arms of a junction at 90° to each other. This just doesn’t happen because, well, it doesn’t make a lot of sense, and would probably be quite unsafe – for motor traffic, at least.

There is now a new junction in Oxford that seems to substantiate this – that you can allow ‘conflicting greens’ on a junction, at 90° to each other (or indeed at other angles). The Hythe Bridge Street junction lies between the city’s station, and the city centre. It used to be composed of two separate roads, with a cut-though in the middle diagonal for walking and cycling –

Screen Shot 2015-03-17 at 19.29.36But it has now been converted into a straightforward crossroads. Or, actually, a slightly less than straightforward crossroads.

The odd arrangement is on the western arm of the junction.

Screen Shot 2015-03-24 at 00.21.58

Looking east, across the junction

The signals tells us that all motor traffic must turn left, heading north. Meanwhile, however, people cycling are exempted from that instruction – they are able to cycle off in any direction they please, north, east, or south.

So far so good, but allowing people cycling to do this actually involves a ‘conflicting green’. While this arm of the junction is green, it turns out that traffic flowing south out of the northern arm also has a green signal.

Screen Shot 2015-03-24 at 00.25.55

Here’s another photograph, this one from Graham Smith, showing the same location, but from the south-western corner of the junction.

Picture by Graham Smith

Picture by Graham Smith

The man on the bike and the van driver both have a green signal. Note that at the time Graham’s picture was taken – January this year – there aren’t any road markings in the junction. Indeed, this was the initial plan, as below.

Hythe Bridge Street

Click to enlarge. I’ve highlighted, in red,  the paragraph that makes clear people cycling can progress in any direction through the junction from the western arm.

Some markings were then hastily added at the end of January, presumably in response to local complaints and actual collisions.

575470.fullA painted waiting area, right in the middle of the junction.

Screen Shot 2015-03-24 at 09.28.17

This is, of course, still far from brilliant – if you are not familiar with the junction, it’s not entirely clear how it will work, and even if you are, you are still exposed to collision risk from motor traffic turning around you, without any protection.

But the main point of this post is that – regardless of the safety implications – it is apparently entirely legal to give green signals, simultaneously, from junctions at 90° to each other, as shown below – even if the ‘traffic’ coming from the western arm is cycle-only.

Hythe Bridge Street


The safety implications of this odd arrangement in Oxford – which involves interactions between bikes and motor traffic – are surely much greater than a clearly-explained simultaneous green layout, which will involve interactions only between people cycling.

So – what’s stopping us?


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14 Responses to Conflicting greens – the implications of a new Oxford junction for ‘simultaneous green’

  1. davidhembrow says:

    This is, simply put, a dreadful junction design. It’s bizarre that the “we can’t do that” excuse is used so often with regard to advanced and safe cycling infrastructure in the UK because it sometimes seems almost anything is possible if it’s unsafe.

    • T.Foxglove says:

      “almost anything is possible if it’s unsafe.”
      As long as it isn’t unsafe for people in motor vehicles.

      My LA installed an advisory cycle lane on an uphill 40mph stretch of road. Following its installation they were concerned to see that motor vehicles were keeping out of the lane and it raised the potential for conflict with motor vehicles coming in the opposite direction down the hill.

      Although there hadn’t been any collisions something had to be done.

      They could have spent some real money on making the cycling facility fit for purpose;
      or they could have reduced the speed limit (a 30 mph limit starts about 50m away) & then narrowed the downhill lane;
      or widen the centre line by introducing hatching thereby encouraging people to drive in the cycle lane.

      Danger averted:

  2. I wonder if the fact that cyclist doesn’t have a green (the green is an arrow for a direction they’re not going), but can simply go because they don’t have a red, is relevant?

  3. Liz says:

    The consultation was apparently pretty quick, they reopened the junction before anyone remembered to add the “Except Cycles” signs, and the cycle waiting area is an after-the-fact attempt to fix a conflict which apparently hadn’t occurred to anyone involved in the junction design – so possibly no one went and checked whether conflicting greens were actually allowed because they hadn’t realised they were building one.

    • Ha, that’s a plausible (and slightly disturbing!) interpretation.

      Even if they genuinely hadn’t realised though, the arrangement they’ve changed it to (adding the markings) still involves conflicting greens, albeit with people expected to give way in the junction. Indeed, I think the use of ‘give ways’ is involved in the TfL diagrams I’ve seen of potential ‘simultaneous green’ arrangements.

    • Eric D says:

      I must confess I initially thought it mean ‘No Left Turn for Cycles’ !
      I wonder if a clever lawyer could argue that it meant ‘Cyclists – ignore these traffic lights.’

  4. Richard says:

    The original design had toucans and narrow shared use pavements. So at least we were spared that.

    Regarding the general point, it’s conflicts between pedestrians and (on-carriageway) vehicles that are explicitly forbidden. You can already have toucans on each arm and a green scramble. You can’t have separately signalled cycle crossings, but you could use red surfacing or similar (or kerbs) to create informal separation of cyclists and pedestrians. But to do it properly takes more space than was available at Hythe Bridge St / Worcester St.

  5. rdrf says:

    Re- T Foxglove’s post (which is not on this specific topic, but still about what Highway Authorities get up to) there has been discussion about the TfL research showing benefits of reducing centre line width and/or removing them altogether. You should be able to use for lobbying engineers in this kind of case.

    Classic risk compensation – drivers are capable of watching out if pushed towards other direction motors.

    In case mentioned, have upward cycle lane or track, narrow centre line or remove it, narrow downward lane with slower speed limit so cyclists can take lane.

    But NOT do what the photo shows!

    • matthewp says:

      Ironically, a week or two before T.Foxglove’s picture was taken, the road was resurfaced. They scraped the surface off all of the road apart from the cycle lane which had been resurfaced a year before when the lane was put in. For a few days, traffic was rumbling up and down the hill with no lane markings other than the cycle lane, and because the cycle lane was slightly higher than the main carriageway, no motor vehicles were driving on it.

      Everything worked fine. Possibly no-one was doing 40mph, but I’d regard that as a good thing when there’s a blind bend and a pedestrian refuge at the bottom of the hill.

  6. platinum says:

    Why does so much focus on what can be achieved through the existing regulations? If the regulations are not fit for purpose then just change them to something that is. It’s not rocket science.

    • MJ Ray says:

      Because the people making the regulations (Whitehall) aren’t the people who can’t do things because of bad regulations (councils and the highways agency)

    • Eric D says:

      Changing regulations isn’t quick and easy – like abolishing ‘Road Tax’ in 1937.
      People are just beginning to accept that it has gone,
      then someone decides to bring it back 78 years later !

  7. The Oxford junction seems to be a completely different concept than the examples from the Netherlands. If I understand the NL junctions, there is simultanous green for cyclists while all cars get red, similar to the pedestrian phases in UK junctions.

    Here in Edinburgh we actually have a junction that (almost) works like the NL examples. The junction at the NW corner of the University’s Kings Buildings campus (Mayfield Rd/West Mains Rd/Esslemont Rd) was redesigned about a year ago. It’s a major entrance for pedestrians and cyclists coming from the centre (there are other gates for vehicles), but it was just a small gap in a hedge, so people filled half the junction as they couldn’t all get through quickly enough. So, pavements were widened, cycle lanes added and new lights installed, and also the entrance to the campus completely redesigned into a wide, open plaza.

    The pedestrian lights were changed to toucan, but they still have the normal pedestrian scramble phase where all motor traffic is stopped and pedestrians (and now cyclists) from all directions have green. The scenes in the morning and afternoon are very much like the NL videos, with cyclists from all directions crossing diagonally, mingling with pedestrians.

    It’s not exactly the same though and a bit more complicated. There are advisory painted cycle lanes leading up to the junction, and just before the junction a shared pavement starts (on three of the four corners of the junction), and campus entrance is also shared ped/cycle area (motor traffic has other entrances). So when you approach the junction, you can hop on the pavement and wait with the pedestrians, and then cross at their phase. Also, if you turn left in some of the corners, you can hop on the pavement and bypass the light completely.

    However, there are also ASLs, and it’s not clear if cyclists who are waiting in them can also use the pedestrian green phase. If you’re going straight across the junction, then the advisory lanes, ASLs and the signals for motor traffic are most sensible rather than the shared pavement and the toucan. But when you want to turn right, you can either use the vehicular way or the pavement/toucan way. When the pedestrian green phase starts when you approach the junction, many cyclists don’t go on the pavement but just go through the ASL and the stop line, which does look like red light jumping (as the light at the stop line is red) although right behind the stop line there is the green toucan.

    But even with this certain amount of confusion I’ve never really seen any conflicts between cyclists and pedestrians there, even though the junction is packed with pedestrians and bikes at rush hour, as it’s still all a bit narrow. Conflicts that I have seen are when cyclists chose the vehicular route and (when turning right) are stuck in the middle of the junction during motor green phases.

  8. Pingback: Oxford road junctions: inhibiting walking and cycling - Oxford Blog

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