One of my most viewed videos is an animation I made in 2011, showing that a common Dutch type of junction design with protected cycle tracks would in principle fit in American streets. To deal with many questions I showed real examples of that particular junction design in a second video. But there were still some unanswered questions that kept coming back and I had therefore planned to make a new follow-up to better explain this type of design. Then Dick van Veen, a Dutch senior city planner and traffic engineer at Mobycon asked me if he could use parts of both my videos for a project earlier this month in Canada. I then decided that the new video had to be made. My own ideas coupled with Dick’s professional expertise led to a new video which he has indeed used in a presentation. I heard it was very well received. I planned to publish a post with this new video on a later date.
But by sheer coincidence David Hembrow then published a follow-up, in which he states that this design is just one of many possible solutions for a junction and that people shouldn’t just focus on this particular solution alone. Then even more coincidental, my initial video got a lot of renewed attention when Nick Falbo published his interpretationof the design and the way it could be implemented in the US. After these publications a lot was written all over the internet in comments, tweets and forum discussions. Prof. Peter Furth from Boston’s Northeastern University showed me some of the questions he had received directly, with his answers that I fully agreed with. With such a commotion it is high time I publish my own follow-up video with an explaining post. So here we go!
Common Dutch Road Design
There are many questions about the status of this design. How common or standard is it? David Hembrow argues it is not the only solution and it is in fact not the most used solution in the area where he lives. I agree with the response of Prof. Peter Furth to this: “That’s true in smaller cities, which have few major traffic roads and where signalized intersections have been replaced with roundabouts in great numbers. But in larger cities, cycle tracks along the main arteries are routine, as are signalized intersections where such arteries meet. And wherever traffic arteries with cycle tracks meet at a signalized intersection, this is the routine, standard design. You can see scores of them in the Hague, Rotterdam, and Amsterdam.”
It is a fact that in the Dutch situation protected cycle tracks alongside main streets do not stop at junctions, but continue in one form or another on the junction itself, so that such a junction can be traversed by people of all ages and abilities (cycling or walking) in a safe and convenient way.
Some people misinterpreted the focus on the protective traffic island in the corners. I started with those in the animation because that was an easy way to explain the design. In reality that island is the last thing on a Dutch designer’s mind.
“These traffic islands are not always the same and not even symmetric, they are the result of the tight radius for right turning cars to decrease their speeds on the intersection and the decision to design the cycle track slightly bent away from the intersection”, explains Dick van Veen. “This not only creates a safe waiting place for people cycling, but also a waiting place for exactly one car in that turn. It is right before the crossing place for people walking and cycling, but it is at the same time out-of-the-way from straight going motor traffic. This is a most important fact that is easily overlooked: the location of the stop line for cyclists. Another reason for the bent out cycle path is to make the distance between the carriage way and the cycle path large enough for a wheel chair or a mother with a baby carriage to stand there and wait for a safe crossing moment.” The advantage of this design is threefold: you create a safe place for motor traffic, for people cycling and for people walking.
The one car length long waiting area in the turn makes that traffic lights can be arranged in a flexible way. In the Dutch situation a straight going cyclist as well as someone crossing the street on foot always have priority over the turning car. So even when the traffic signals are not working the car must wait and has a place to safely do so. When there are traffic signals the best solution is a separate green phase for straight going cyclists and turning cars. “But,” adds Dick van Veen, “no extra phase for cycling is needed. Dutch traffic signals work in a more sophisticated way and an intelligent and complex way of creating signal phases makes it possible that traffic in completely different directions, especially also people cycling, can have green at the same moment together with pedestrians, or cars turning in another direction. The total waiting times for any type of traffic are then almost always under one minute, which is to keep traffic flow high and to discourage red light jumping.”
Dutch junction design has developed further and a more modern solution is the Dutch single lane roundabout. Dick van Veen says: “This has been proven to be much safer because first of all a roundabout reduces conflict between motor vehicles. The tight dimensions decrease the speeds and at 20km/h everything becomes much safer. These roundabouts eliminate high-speed right-angle collisions because only head-to-tail collisions at lower speeds can occur. And second, different types of traffic cross each other’s path exactly where the speeds are lowest instead of where they are highest, which is the case on a traditional crossroads. Space is not the issue. A roundabout does not need more space than a crossroads. A circle with a diameter of 15 or 16 metres is already within accepted standards.” That the Dutch roundabout, including the cycle tracks all around it, can be built in almost the same space of a traditional junction is the reason why so many are being converted.
There are other developments too. In streets with a maximum speed of 30km/h separated cycling infrastructure is not necessary. Since the Netherlands now has about 35,000 kilometres of streets with such a speed limit we don’t see the design there. What we do see a lot is unbundling of different types of traffic at route level. What mostly happens is that through motor traffic gets a new detour around a certain area and the original direct routes with a substantially decreased volume of motor traffic can then be changed into a through route for cycling. Possibly as fietsstraat (a cycle street where motor traffic is not allowed to overtake people cycling). Such cycle routes then only cross main motor traffic routes at fewer places. This makes the construction of grade separated solutions feasible in terms of cost and space needed.
Good solution for (signalised) junctions
So there is an array of measures from which Dutch road designers can choose what is best for a particular situation. But in busy and older down town areas in larger cities there is often no space for the more elaborate measures with detours and tunnels or overpasses. And although even there we see an increasing number of roundabouts, this type of junction design – a crossroads with cycle paths around it, most often signalised – will remain the safest solution for a lot of places in the Netherlands.
Since many cities in the world have such signalised junctions, this solution to make cycling safer might work there too. So it is great to see a good interpretation like the oneNick Falbo has made.
Dutch junction design looks great! What is problematic here in the United States are actual bike lanes themselves. We do little really to handle junction and focus more on bike lanes. But here in the U.S. bike lanes suffer from their positioning. If you have wretched winters with lots of snow and very little plowing of that snow you end up with nearly unrideable streets. Of course separate cycle tracks in what is now the place for sidewalks really does not help if they too are not properly plowed. In short bike lanes positioned on the sides of streets or even beside sidewalks are largely ignored in bad weather. The costs for special smaller equipment to clear these narrower lanes is expensive and because of their size they are less efficient in terms of speed of snow removal.
We Yanks understand plowing. We shove snow to the side and deal with it much later by using front loaders to either move it to special intersections from which it is trucked away or something similar. Frankly, my sense of how Americans deal with bike lanes is that we are much better off if the lanes are centered over the crown of the street.
Dutch Junction Design could work even with such lane positioning. And that is what I would hope eventually wins out. But leaving the lanes snugged up against the existing curbs is in my judgment a practice which will eventually have to be abandoned if we really want to get sustainable lane design that is indeed affordable when it comes to maintenance. And please do not tell me that you think PVC pipes are an effective way of segregating these lanes from those occupied by other traffic forms. They are ugly and hardly worth the effort to install.