Grade separated roundabout – the safest solution for a junction

In my ongoing series about safer junctions I have covered Dutch junction design and how it differs from that of other countries. I then showed you that the Dutch have now discovered that urban roundabouts are safer than cross roads junctions when they are built to a specific design and give cyclists priority.

As stated in that story the first modern roundabout with priority for cyclists was in Enschede and as it turns out Fietsberaad has a file with a lot of background information about this good practice example.

So could it be any safer? Yes, multi level solutions (grade separated) are even better.

Multi-level roundabout in the former-ring road, now inner connector road of Houten

This roundabout in Houten has two levels of completely separate roundabouts. One for motorised traffic and one for cyclists. As you can see in the video there is no conflict at all anymore between these different modes. If you want a junction to be safe this is really state of the art design.

It is not a spectacular video, but you loose the “excitement” on the streets when you eliminate all conflict. It does show how junctions can be made safe to use for all.

This multi-level roundabout was part of the tour of the Australians when we showed them Houten last Saturday. It can be found in the former South part of the ring road of the first new Houten. When new Houten was expanded from the 1990s this road became the only shortcut for cars in the city.

Original Houten in red. The first new Houten (1) and the second new Houten (2). The former South part of the first city ring road is now a short cut between part 1 and 2. The arrow points to the multi-level roundabout.

So is this a rare example? No it isn’t. Multi-level solutions exist all over the Netherlands and they have been around for at least 70 years. The multi-level roundabout in Utrecht in the video below is showing that very clearly. (The roundabout for cyclists was in this case turned into a T-junction some years ago but the zero-conflict situation with the roundabout for motorised traffic remained.)

Of course,  not all junctions can or should be changed into a (multi-level) roundabout. But for some key junctions it can make the essential difference between a pleasant ride and a barrier that cannot be taken.

This post, written by me, was first published on a different platform.

The original comments:

examinedspoke said… This kind of infrastructure is beautiful, but almost unintelligible to me. I simply don’t see how one goes from what we have now in Los Angeles to that. The changes required are breathtaking: political will, rewritten standards, funding, etc. Making such changes would really require “loosing excitement” onto the streets, and in ways that I can’t quite imagine now. But, as always, fingers crossed… 26 May 2011 07:21

Tejvan Pettinger said… Very interesting. We have a multi level roundabout near where I live, except it is prohibited to cycle under the roundabout. you are supposed to get off and walk. (It is also prohibited to cycle on the roundabout) 26 May 2011 09:06

lee said… There are some junctions like that in England. I believe there is one in rotherham, when I last used it the underpasses were sprawled with graffiti and covered in broken glass which seems to be common with underpasses in Britain meaning they are rarely built nowadays. A cycle underpass in my home town was filled in and replaced with a signalised crossing due to ‘social’ problems with it. 26 May 2011 09:51

Anonymous said… There are a lot of these in Milton Keynes, often with a displaced arm design, the cycle and walk way being turned 45 degrees from the roads resulting in an inner cross roads for bikes. It is a good system although in the past it has been difficult to navigate these routes. Signage has been improved but it remains a very different view of the city. Mark Garrett, Bristol UK 26 May 2011 15:36

christhebull said… And not only are multi level solutions safer, they reduce delays for all road users, which is why interchanges are the preferred option on major dual carriageways and motorways. However, one should be mindful of the motivation behind both cycle and pedestrian underpasses – are they simply a way to get non motorised traffic out of the way, or do they form part of a genuinely useful network of cycle routes? In the UK, the former is the case, especially in situations where the road is over-engineered in terms of speed for its location. Guildford has a gyratory system, which as well as incorporating a pre existing street that forms a major pedestrian route and is also home to several bars and clubs, has another section with no at grade pedestrian access. Of course, pedestrians are not forbidden from this road. They are, however, corrrelled into underpasses and walkways; and therefore it should be noted that whilst multi level solutions may be good at major junctions, those “major junctions” shouldn’t dominate town centres in the first place, and the multi level solution is probably better further out where traffic is faster and the safety benefits greater. 26 May 2011 19:45

Mark Wagenbuur said… @Christhebull; exactly right. This solution is only suitable for major junctions with a high volume of traffic and not in city centers. That is what I meant with my last sentence. Both the examples I show in the videos are in (former) circular roads. Social safety in tunnels is always very important. The Dutch also used to have narrow dark tunnels that were terrible, but once they were built wider and lighter they were a lot more inviting. But maintenance is very important! As it is with all (cycle) infrastructure. 27 May 2011 10:05

Micheal Blue said… Looks great! They also seem to take lots of space, so proper planning right from the beginning is probably required. And look, Mark, you do have hills – coming from the underpass back to the street level. Mark, since you produce nice videos, it would be great to see one from a hilly portion of your country…if there is one 😉 If you decide to come to Canada, I can give you a free study tour of hills, and show you how to properly run away from a bear. Well, more seriously, there are beautiful country vistas to bike through here, so if you decide to visit, you can let me know. 27 May 2011 17:45

Anonymous said… The subject of underpasses in general is actually a good one, the ones I’ve seen in the UK, for example, have been dreadful. Some of the tricks used these days by the Dutch include:
• Having a wide, gently sloping, open approach right until the point where it passes under the roadway for maximum visibility.
• Sloping walls in the tunnel itself to provide the illusion of width and make it a less appealing place for ne’er-do-wells to hang out.
• Bright lights, obviously.
• Graffiti-resistant tiles in bright colours, preferably largely white.
• A gap between the carriageways to let in natural light. The tunnels in these two videos don’t show any of these advances, as they’ve been built decades ago. 27 May 2011 17:55

Mark Wagenbuur said… @Michael Blue; thanks and yes we do have hills in the Netherlands and I did film some of them. See this blogpost .  There is another post too:  @Anonymous; all the ‘tricks’ you mention are right and used. They can be seen in the second movie in the other tunnels and also in the 70yo tunnels you see the bright graffiti resistant tiles were added recently. 27 May 2011 23:11

Anonymous said… I found an example of a well-designed underpass that follows all the current design recommendations in the Fietsberaad Flickr stream. There’s various other modern designs in there as well. 29 May 2011 12:09

7 thoughts on “Grade separated roundabout – the safest solution for a junction

  1. It occurs to me that the Utrecht underpass you shown was being built in WW2, after the Blitzkrieg into the Netherlands. I wonder what else was being build under Nazi occupation.

    1. Lots of things were built during WWII. Not everything stopped right away. Things that had already started were finished as planned. Only when resourses became unavailable towards the end of the war developments stopped. The Maastunnel in Rotterdam was also finished during WWII.

      1. I also wonder if the Nazis used the development as propaganda. Not hard to claim you are a good country if the territory you control is still developing as normal (as normal as it can be under occupation). Also, how are you not making cycling videos every day? (I mean this as not criticism of how often you can, as you have to research some projects, actually get to the places you are filming, simple if the place is in S’Hertogenbosch or Utrecht, harder if outside said municipalities, but still convenient train service. I have a feeling you responded to my question which I posed in the middle of the night where I am due to time zones. You also have regular work (if you are ok with it, what do you work as? Not train conductor, not forced labourer, so what do you work as), and a family most likely. Then you are swimming each week in Vulgt. Also, that donations thing may work better if you try something that John Green and his brother made, that ended up merging with some other company that deals with that. 6000 subscribers, even assuming only 1200 of them donate, even 7 dollars (CAD) a month, gives you more than 100 thousand to maintain yourself and and family do cycling videos full time, which should not be too difficult, considering that you already cycle so much that it is like driving a car to most Americans, minus congestion, some research for projects like the video outlining how winter cycling is possible in your far famed land (you may know the joke I am making if you know what the de facto anthem of Canada was before 1980), and a computer with which to type, something that almost all people in the industrialized world know how to do. What language do you think in, I know you talk in English, German Dutch (obviously) and French.

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