Legality of Simultaneous Green/Cycle Scramble in the UK

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AndyR
Legality of Simultaneous Green/Cycle Scramble in the UK

Talking to the representative from TRL at yesterday's Cycle City presentations, about the various trials they carried out for TfL at the end of last year, he seemed to be under the impression that a simultaneous green for cyclists was presently legally OK. Unfortunately I have previously spoken to others who are emphatic that this is not the case.

As someone who is not well versed in the intricacies of traffic light installations, is there anyone out there who has a definitive answer (preferably quoting chapter and verse of the relevant regs)?

BTW, I was also gratified to find out that the trials seem to have been more wider-ranging than what has been published (i.e. only being able to show the same aspect as the main signal heads or only having a limited early start).

tombaileytyne

you can certainly achieve something like it by putting Toucans on all arms of a junction and triggering a barnes dance, then either design so the cycle lanes or tracks transition into the toucan, maybe as parralel crossing, or more usually turn a blind eye to people crossing stop lines on carriageway.

As Easy As Ridi...

My understanding is that it is possible to create a simultaneous green junction in the UK, and I know that TfL are working on plans for inclusion in the new LCDS.

Obviously all motor vehicles will be held at red signals - so no conflict there. Pedestrian/cycle conflicts can be managed 'outside' the signalised area of the junction, effectively like the Dutch do, with cycle tracks passing around the corners, and pedestrians crossing these informally.

As far as I know, the main problem is conflicting movements of cycles in the all-green stage, in the centre of the junction. While we are allowed conflicting movements on green from opposite directions of a junction (e.g. motor vehicles turning right across each other, from opposite sides of the junction) it is *not* allowed for simultaneous green movements from *perpendicular* directions.

The work-around that TfL are employing is to use give way markings for cycles within the junction, beyond the signals. It resembles a Dutch junction, but with the paths through the junction 'managed'. A little hard to explain without the diagrams! I will see if they can be shared.

Mark

AndyR

Thanks. If there is a possibility of seeng actual proposals that would be great.

My thought (which it turns out TRD did try) would be to place the ASL in front of the ped crossing - in theory preventing encroachment into it by motor vehicles - and use two low-level (LL) signals. The first LL signal would be placed at the normal stopline adjacent motor vehicles. The second at the ASL. The first signal is a 'gate' that controls entry to the ASL, the second is for the simultaneous green on each arm. Essentially the first LL signal would be on green at all times except when either peds are using the crossing or the adjacent motor vehicles have green. This would allow the ASL to fill up and once the ASL had green the first set of signals -the gate - would go red, to allow the ASL area to clear out (therefore removing the problem of cyclists being left in the ASL reservoir and being hit from behind by motor vehicles). The placement of the ASL in front of everyone else would also reduce the distance cyclists would need to travel in order to clear the junction.

This layout (which should really only be a last-resort retrofit for existing signalised junctions where cyclists couldn't be properly segregated for whatever reason) at least has the advantage of completely separating cyclists from motor vehicles in space and in time and should (if everyone actually took notice of the lights) get rid of the left-hook problem.

It's also more compact than the arrangement suggested at Cycle City whereby each turning movement is separated into its own lane - if you've got that much space then why aren't you physically separating cyclists from motor vehicles?

To me, this layout seems much safer than the simple early start that seems to be the TRL/TfL preferred option, and which still allows for the left-hook of those cyclists unfortunate enough to be fifth or sixth in the queue.

Comments, please.

 

(BTW, do you know where the bit about 'simultaneous perpendicular movements' not being allowed is from?)

pete owens

Surely, the entire point of a green light is that it indicates priority and guaruntees that conflicting traffic movements are held at red.

Now, I can understand that a junction can operate with no priority - ie a duty of everyone to take care. But simultaneous green would give cyclists from different directions the impression that they had right of way over each other.

Perhaps this situation could be indicated by a flashing amber lights rather than giving a green to everyone.

AndyR

TBH I think a flashing amber 'go with extreme caution' (as in the Republic of Ireland?) would give the DfT an even greater attack of the vapours than simultaneous green.

A green arrow guarantees priority and no conflicting movements, a green circle is proceed with caution, so we accept some degree of conflict already.

pete owens

The only time the green circle does not give you priority is if you are turning right across oncoming traffic. ie it creates EXACTLY the same situation that you would have at a cross roads where you have marked priority. If you are going straight ahead at a green light you do not expect to be T-boned by crossing traffic.

So if you want to let E-W traffic proceed at the same time as N-S traffic then "Go with extreme caution" is exactly the right message to convey.

tombaileytyne

Sustrans & Glasgow Council tried and failed to get DfT to authorise flashing amber for Connect2  scheme there, despite producing all sorts of evidence.

AndyR

I think the DfT want something that looks familiar, i.e. red, red-amber, green, amber, red, for vehicle signals. Going from a steady to a flashing signal, or vice-versa, appears to be anathema to them. The way the low-level signals operate in my example above at least has this going for it.

pete owens

Well if they want the standard signals then they will certainly want those signals to have the same meaning.

 

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