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| An aspiration for London |
I first saw this image a few minutes after returning from the centre of Assen. As it happens, on our most direct route to the centre of the city, I pass a junction which looks remarkably similar to a mirror image of what is being proposed in London and I thought I had to write about the similarity.
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| Real life in Assen |
The Assen junction solves problems which the London junction will suffer from - notably the ability of drivers to intimidate cyclists and to turn across their paths. The design in London requires drivers to turn left immediately after the traffic lights, crossing the route of cyclists, in order to reach some destinations. Cyclists are encouraged to take up position in a wide bike box depending on which direction they wish to cycle in.
The Assen junction is not part of a roundabout. Roundabouts in Assen have been described thoroughly before: Not one of them has bike lanes on road. Not one of them includes bike boxes. Not one of them puts cyclists in a position such as is proposed in London.
I don't much like advanced stop lines (aka "bike boxes"). Cyclists filtering through traffic to reach a bike box can find themselves an unpleasant situation on the wrong side of turning vehicles when the lights change. They can be subject to intimidation by drivers behind them, and upon reaching the bike box a cyclist can find that it is already full of cars or motorbikes. On a multi-lane road like this, there are many points of conflict where cyclists and drivers will have to cross each others' paths. It's a world away from sustainable safety:
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| Bow redesign includes plenty of scope for conflict between cyclists and drivers "sharing" a giant roundabout together. Not only the routes but also the speeds are different, leading to many points of conflict. |
And that brings us to perhaps the most important difference between these two junctions. While the mega-city of London sees it as aspirational to install an advanced stop line on a roundabout to give cyclists a very slight advantage on the "superhighways", plans are afoot in small towns right across the Netherlands to make further improvements on already are better junction designs. Bike boxes are not something which should still be part of new designs, especially on busy junctions. Rather, they're an idea which both campaigners and planners should be looking beyond.
Lessons still need to be learned even from what will soon be removed in the Netherlands, so I've documented some details of the junction in Assen below:
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| Cyclists stop 13 m ahead of drivers. Click photo for larger size |
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| All conflict is removed at this junction (some appears slightly later on, but it's certainly not comparable with Bow roundabout) |
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| Drivers cannot turn right, but cyclists can. |
It is extremely positive that TfL seems to be thinking about cyclists. That they've proposed their redesign in the face of criticism is a sign that a positive change has taken place within the organisation. However, the proposal that they've put forward is inadequate.
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| People feel relaxed enough to cycle through "no hands". Will this be true in London ? |
Exactly the same problems arise in the Netherlands as in the UK, however the approaches taken to deal with them, without putting cyclists into the firing line, are very much more advanced. In May we're running another infrastructure Study Tour here in Assen and Groningen.
If anyone from Transport for London is interested in seeing a very different way of designing cycling infrastructure they might like to book a tour. Why keep trying to re-invent the wheel ?
Read more posts about Advanced Stop Lines ( Bike Boxes )
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4 reacties:
Eloquently said, as always. To create subjective safety, remove conflicts - it's as simple as drawing coloured lines on a plan. Perhaps TfL could do with some new felt-tip pens?
The original reaction was fairly positive, as the "early start" traffic lights at the end of the cycle lane sounded like they would have a short cycle only phase, similar to certain bus gates.
However, it was realised that all the cycle light would do is control access to the ASL by making it slightly safer to undertake other traffic to enter it (assuming traffic hasn't entered it illegally or is simply queuing across it due to congestion), with the head start being merely the time it would take for a driver waiting a few metres behind a cyclist to catch up with them. Meanwhile cyclists who use the cycle lane when traffic in the same direction is moving will get a red light, and it wouldn't surprise me if people either ignore the cycle lane completely, or jump the red light and risk getting left hooked.
It is worth pointing out that Paul James came up with an alternate turbo roundabout based on the premise that while most pedestrian and cycle movement is west to east, most motor traffic is turning left or right, because through traffic can take the underpass or flyover, with the exception of access to side roads in the immediate vicinity and buses which stop on the slip roads.
North to south cyclist movement is however insignificant - to the south the A12 goes through the Blackwall Tunnel where cyclists are prohibited, and cyclists are also prohibited to the north on the section of the road that is a former motorway (the only reason it was downgraded along with the A40 Westway was due to a legislative blunder that prevented TfL from managing motorways. It still looks the same, but doesn't have blue signs any more.)
David, nice to see you blogging again ;)
For anyone involved in city planning I highly recommend Hembrow's study tour.
Last autumn we took part in it and I'm really surprised to observe, that architects, who ride by bike to work, learned many things they didn't know before the tour.
It's obvious, that it is better one time to FEEL how things works than hundred times to read about that.
Hi David,
So basically your point is that with the shielded bike lane, advanced stop points and right traffic light timings, there is as little conflict as possible. I understand that the aim should be that for both drivers and cyclists there should be the least possible things to watch out for. Roundabouts are very busy to begin with, with al the signs,turns and other drivers, so drivers don't need people on bikes crossing unexpectedly. So yes, make the road so that everyone just behaves predictably. Mark has already pointed out in his excellent videos that the line of sight is so important, which corroborates with your video. Best practice would bee to have a separate cycle track some feet away from the roundabout, with the crossings several meters (1.5 carlengths) away from the roundabout, so drivers have room to stop for cyclists. But you know all that.
What you propose is very compact, and I have to say instead of a right turn (left on the Bow roundabout of course), your video shows an interval for traffic coming in from the left. Doesn't that change the way space is needed for the turn?
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