Tuesday, 24 January 2012

Turbo Roundabouts. Be careful what you wish for.

After writing about Bow Roundabout in London a week ago, I looked around and found other people had done the same. However, at least two had proposed what is very much the wrong solution. The idea of a "Turbo Roundabout" came up on both the Cyclists in the City and Pedestrianise London blogs. It's not the right solution.

Sometimes you have to be careful what you wish for. If you're not absolutely sure what a Turbo Roundabout is (in particularly, a "turbo-roundabout" as might be implemented by TfL) and not absolutely sure that it is what you want, then don't ask for one.

This video from the Fietsberaad shows a "Semi"-Turbo Roundabout in Hilversum. It initially appears to work quite well in the video designed to promote the idea, but this is merely a "semi-turbo" roundabout and in many ways actually more closely resembles normal Dutch roundabouts. I caution to look out for where there are two lanes of motor vehicles which need to be crossed at once by cyclists and pedestrians - a case which is excluded from the video:

The next video came up as a related video on youtube. It's a simulation of a Signalised Turbo Roundabout. It shows how motor-vehicles flow nicely around the roundabout, but there is no consideration of cyclists or pedestrians in the simulation:

Indeed, the whole point of the turbo roundabout is to "improve traffic flow". Turbo-roundabouts were never intended to make things better for cyclists or pedestrians. Cyclists don't much like them. The Fietsersbond (Cyclists' Union) in the Netherlands has complained about unacceptably long crossing delay times for cyclists at Turbo Roundabouts.

As I said before, "be careful what you wish for". Why ? You might end up with something similar to what is in the next video - a real, live, turbo roundabout in Eindhoven videoed by someone who isn't trying to sell the concept. The title is "Floraplein in Eindhoven very dangerous for cyclists":

Note how crossing double exit lanes causes trouble for cyclists.

So what's the alternative ? I didn't have any photos or videos of my own to show here because we don't have turbo roundabouts in this area. In fact I've documented before what all the roundabouts in Assen look like. None are turbo roundabouts, and none cause problems for cyclists.

Some other ideas are pointed to by the website set up by people who are campaigning to improve or replace the Floraplein turbo-roundabout. It includes a link to an interesting presentation about alternatives to turbo-roundabouts written by Peter Kroeze of Ligtermoet and Partners.

When observing from afar it can be difficult to tell what really works from what does not work. We've already seen both shared space and strict liability given far too much credit for the cycling conditions in the Netherlands. Let's not add Turbo Roundabouts to the list of things that are misunderstood.

If you want to know what real Dutch cycling infrastructure is really like, why it works, and why cycling is so popular and so safe here, please book a study tour. Not many people have the experience that we have of living and cycling in two countries as different as the UK and the Netherlands, and we can pass a lot of this knowledge on within a few days. Reading blogs like this, reading articles and looking at Google Streetview can only get you so far.

2013 update - Bedford in the UK building a turbo-roundabout 'for cyclists'
A year after posting this blog post, warning that Turbo Roundabouts, no matter how attractive the name sounded, were never intended to be used by cyclists, a story appeared about the "walking and cycling officer" of Bedford in the UK was proposing to use "Dutch experience to improve cycle safety" by building a turbo roundabout which is actually worse than the example from Eindhoven shown in the video above because there is to be no cycling infrastructure at all.

In Bedford cyclists will be asked to
give-way or dismount by these signs,
which have never been used before.
If changing the law, why not do it
for something more worthwhile ?
On the Bedford turbo roundabout, cyclists are supposed to either share the road with cars or to cross the road like pedestrians. They are branding this as "Dutch" even though it is something which you would absolutely never see in the Netherlands. Frankly, it's difficult to imagine a larger mistake than this.

This recalls an online conversation which I had in 2011 with another Bedfordshire planner. He also wanted to build a "Dutch" roundabout which omitted cycling infrastructure. Various reasons why were given, including the "difficulty" of combining existing on-road cycle-lanes with a Dutch style roundabout which had cycle-paths and his idea that "not all" Dutch roundabouts had separate cycle-paths.

The discussion with the Bedford planner prompted two blog posts from me to illustrate what I had said to him in email. One of these posts demonstrated that there is no problem at all in merging from an on-road cycle-lane onto a properly designed Dutch roundabout. The other post demonstrated how every single roundabout in Assen has separate facilities for cycling because that is the norm in the Netherlands. His concept of a "Dutch" roundabout without separate cycling infrastructure was not similar to real Dutch infrastructure.

Cycling infrastructure is not an optional extra on roundabouts. Where cyclists have to use the same roundabout junction, specific infrastructure must be provided.

It's disappointing that after having had this long conversation and tried to explain to one Bedford planner, another should still have similar misconceptions two years later. Note that the first Bedford planner also pushed through his flawed ideas, building a dangerous design of roundabout branded as "Dutch" in Cambridge.

Signed off by campaigners
Despite my warning and others, this project continued. Further investigation by myself in 2014 revealed that the Turbo Roundabout in Bedford had been signed off by representatives of several British cycle campaigning organisations: Tony Russell (Sustrans), John Franklin (Cycle Nation), Chris Peck (CTC), Ruth Jackson (British Cycling), Ralph Smyth (CfPRE) as well as Robert Semple (Transport for London).

It's extremely disappointing to find that campaigners have such low aspirations as to rubber stamp a proposal which is as dangerous for cyclists as this roundabout design.

Update 2015
No on-carriageway markings
Carriageway exit angle too sharp
Double Yellow Lines over c/w exit
downloadable report is now available about this roundabout. One image, along with its caption, is shown on the right.

I recommend reading the report in full. Amongst other conclusions, it is said that "Arrangement of cycle crossings maximises possibility of conflict between cyclist and pedestrian"which shows the many problems caused by the design used in Bedford.

This mistake should not be repeated.

Find out about proper infrastructure designs.
We run cycling infrastructure study tours precisely in order to try to help councils like Bedford to not make such expensive and dangerous mistakes as this one. Planners need to be educated. They need to learn from the best examples and not just guess at what they think best practice might be. We'd be very happy to host a contingent from Bedford if they'd like to see what the Dutch really do so that future "Dutch" innovation in Bedford can be inspired by the real Dutch infrastructure.

2013 second update
The British arm of a Dutch based company has proposed turbo roundabouts for the UK which I believe would not be built in the Netherlands. Read a blog post about this, including pictures of real Dutch Turbo Roundabouts.

Also read a blog post which summarises several things which are "Dutch" but which should not serve as inspiration.

2014 update. Assen is building a turbo roundabout
Assen is building a turbo roundabout to serve a motorway junction in the south of the city. As such, it is correctly being built in a place where there are many motor vehicles but where neither pedestrians nor cyclists have any reason to go. Watch a video showing this roundabout and how difficult it is even to get near it by bicycle.


David Arditti said...

I have not experienced turbo roundabouts, but from what I have read, their principal rationale is driver safety combined with throughput. They are supposed to be a safer substitute for motorists than the type of multi-lane roundabout we have everywhere in the UK (shared of course, dangerously, with cyclists), without loss of capacity.

That understood, they have nothing to do with cycling, and the examples that I have seen, in example, from SWOV publications, tend to have cycle paths on a different level, with no intersections with the roads. Though I have mentioned turbo roundabouts on my blog, I have mentioned them in connection with the concept of sustainable safety as including motorists, rather than as having any direct benefit for cycling.

It seems that the lesson is that turbo roundabouts are really motorway-type features to be deployed in places where cycle paths can be completely separated from the roads, in the countryside or in complete new-build urban environments. They are less applicable to old urban environments where at-grade crossings will be used.

Tallycyclist said...

The video of the turbo roundabout in Eindhoven is quite atrocious. The endless stream of motor traffic make crossing impossible essentially. The cyclist and some of the scooter-riders finally crossed out of frustration from waiting, and the car traffic had to slow almost to a stop. Such crossings would be considered bad even in many places in the states, let alone in a country like Holland.

Are lots of people complaining about this roundabout in Eindhoven? Or are there much better alternative junctions for crossing that most cyclist use instead?

David Hembrow said...

Tallycyclist: The first place that we considered moving to in the Netherlands was Eindhoven. Due to it being the home of Philips (the connection goes deep: the famous local football team PSV = Philips Sport Vereniging / Philips Sport Club), there are any number of electronics businesses there and that suited me as a software engineer.

Anyway, this means we spent quite a lot of time in the area looking around. While Eindhoven's infrastructure may not be the best in the Netherlands, I certainly had no trouble with getting around by bike. I don't know the Floraplein roundabout, but I suspect there is a better route for most cyclists.

Youtube has some of my early videos of infrastructure in Eindhoven.

Severin said...

I hope to attend one of you study tours in the future, though might be a couple years if you'll still be offering them....

l' homme au velo said...

In the first Video the last part of it was very dangerous with Traffic flying around that Roundabout. In the last Video of Eindhoven it looks Lethal,the Cyclists are dicing with death.

Ordinary Roundabouts are terrible but that one was really bad. Our Roundabouts are very bad particulary the very big ones,but if they tried to put one of those Turbo ones in Dublin it would be lethal the way our motorists behave.

Paul James said...

Thanks for the post David, I've had similar experiences with small turbo-roundabouts in South Holland when traffic flows are high and it takes a long time to cross by bike unless a driver gives way.

My post about Bow however was specifically talking about signalised turbo's with bicycle signal phases combined into the motorised traffic signal phases.

David Hembrow said...

Paul: I take your point about Bow. Signalization changes how things work and can improve them a lot.

However, I still don't think that Turbo Roundabouts actually do much for cyclists.

Large road junctions in general are not really positive for cyclists and avoiding such junctions is the best solution.

This is quite common in the Netherlands. At first you don't necessarily even realize it's happening, but somehow cycle journeys involve few stops for junctions. We've several examples of this on the blog, including this one near our home which feels so very different by bike to how it is by car.

Duncan Kay said...

And now UK funds earmarked to improve cyclists' safety at junctions are being used to build a turbo roundabout in Bedford: https://www.transportxtra.com/magazines/local_transport_today/news/?id=34392

David Hembrow said...

Duncan: It's unfortunately the case that British transport professionals don't understand what the Dutch have achieved or how they achieved it.

I note that the Bedford example is actually not going to have any separate cycling infrastructure at all. This is totally contrary to Dutch practice (which I've documented many times on this blog) and makes an utter mockery of the idea that this is design has anything to do with improving conditions for cycling.

Unfortunately this is another example in a long history of Britain either completely ignoring Dutch practice, misinterpreting it, or picking up on the wrong things.

We run study tours specifically in order to try to break through the gap of understanding which exists between the Dutch and the British but unfortunately British professionals appear not to think they need our help...

Hayate said...

Surely all that needs to change to fix the Eindhoven roundabout is to give cyclists priority, like in the first video?

David Hembrow said...

Hayate: It's never that simple. Relative to more normal Dutch roundabout design, a Turbo Roundabout encourages higher speeds. This combines with requiring cyclists and pedestrians to cross two lanes of cars in one go to create a dangerous situation.

The roundabout shown in the first video and used to sell the concept is only a "semi-turbo" roundabout and only shares some of the problems.

Eric D said...

A new consultation is open

"new island would be shared by pedestrians and cyclists to enable cyclists to cross Stratford High Street to access the towpath"

No mention of making the 'stop twice' facility into a real 'early start' !