Dutch roundabouts have received a lot of publicity, notably here: https://bicycledutch.wordpress.com/tag/roundabout/
Roundabout design in the Netherlands has seen a long process of trial and error. A design used until bicyclists complained strongly enough about it placed the bikeway away from the circular roadway, but cyclists were required to yield. Here is an explanation of Dutch roundabout design developments.
The current preferred design places the bikeway away from the circular roadway, and motorists are required to yield, as shown in this video below. That clears up yielding issues.
Here is a video of a roundabout outside the city of s’Hertogenbosch, put forward as an example of good design.
There is a long discussion of this roundabout, among others, on Facebook.
This is a rather large roundabout at the intersection of major highways, and with moderate deflection on entry or exit. Looking here in Google Maps, it’s clear that the highway in the background at the left is a bypass around the city of s’Hertogenbosch — though not a limited-access highway like the one which appears in the distant background in the video.
This roundabout was constructed in connection with the new bypass road around the city. Google Street View from 2009 shows the roundabout under construction. A sidelight on this observation is that Dutch practice does consider motor traffic. Two of the legs of the intersection at the roundabout are new roads being constructed at the same time.
I’ve been told by a knowledgeable person that the bikeways on either side of the highways are supposed to be one-way, but the only destinations along these bikeways are at intersections — reducing the temptation to ride opposite traffic.
The design requires a lot of space because the circular bikeway is much larger than the circular roadway. The roundabout is outside a city, but nonetheless, it appears that several houses had to be demolished or moved to make way for this roundabout.
The installation here places separate bikeways (red asphalt) and walkways (paver blocks) outside the circular roadway. Bicycle traffic shown in the video is light. If bicycle traffic were heavy, it would result in congestion of motor traffic because motorists yielding to cyclists could not enter or exit the roundabout. Having a path (or for that matter, crosswalks) around the outside of a roundabout obviates the main advantage of the roundabout, that traffic can keep moving. Only grade separation would avoid this for both bicyclists and pedestrians. Motor vehicles and bicycles sharing the roadway would avoid the bicyclists’ causing congestion, but would not be as attractive for bicyclists lacking in skill and confidence.
If you look at the video full-screen, you can see a number of details which are not evident in the small window on this page. I am most interested in the interactions and negotiations for right of way, which are the central issue with mobility and safety in any intersection which is not traffic-signal controlled.
Expectation in the Netherlands is that motorists will yield wherever they see shark-tooth markings. The path around the outside of the roundabout is brought out to the entry and exit roads at a right angle and far enough outside the roundabout so that motorists will be able to see approaching bicyclists. Ohio resident Patricia Kovacs has investigated roundabouts in that state and demonstrated that motorists don’t even yield to pedestrians. She has posted some comments about roundabouts on this blog and in the Facebook thread mentioned earlier.
Some cyclists in the s’Hertogenbosch video are shown looking to their right as they pass paths coming in from their right, for example at 0:55 and 2:25, but many are shown not turning their heads to look for conflicting motor traffic. That is to say, they are putting their complete faith and trust in motorists to yield to them, which is a comment on Dutch expectations for motorist conduct. There is an especially stunning example of this at 1:59, where a cyclist powers through an intersection as motorists approach from the left, inside the roundabout, and the right, entering it. However, at 6:07, a motorist stops abruptly at an exit to the roundabout as a fast cyclist comes around from the right.
One cyclist leaves the roundabout on the left side, opposite the intended direction, at 1:38 in the video. Another is riding around the roundabout clockwise at 2:40 and apparently while talking on a mobile phone.
At 2:34, a motorist is shown slowing to yield to a cyclist who turns right rather than to cross the exit of the roundabout. With no lane changing or negotiation betwen motorists and cyclists, the motorist did not have a way to know which way the cyclist would go.
Cyclists carry various objects in their hands or on the handlebars. At 6:40, a cyclist is carrying something which looks like a hockey stick.
At 7:18 a young woman has a disabled bicycle and is walking.
Now let’s look at some other Dutch roundabouts.
A roundabout inside s’Hertogenbosch, here, has the bikeway immediately adjacent to the circular roadway, so that cyclists are hidden directly behind — not next to — exiting vehicles.
Here’s the video of the roundabout. The video shows motorists required to yield to cyclists in spite of this right-hook threat.Are the cycling facilities safe, as claimed? Or if safety is achieved here, is it maybe achieved in another way? You decide.
The description of the video indicates that this roundabout is rather new. Its design appears to be restricted by the small available space at an urban intersection.
Some notable interactions:
At 0:20, a car brakes rather abruptly. Shortly thereafter, a motor scooter passes through the roundabout on the roadway.
At 0:30 and again at 0:53, a car blocks the bikeway to allow a pedestrian to cross in a crosswalk which is just outside the bikeway.
Most bicyclists are not paying any attention to the traffic in the roundabout, At 0:45, a bicyclist is looking down at a cell phone, but at 0:50, 1:10, 1:29, 1:53, 2:03 and 2:10, and a few additional times, bicyclists perform a shoulder check. The one at 2:03 does this while also carrying a cell phone in one hand.
At 1:49 and again at 2:20, there is a motorcycle in the bikeway, waiting along with bicyclists to enter the roundabout, and there is a bicyclist standing over his bicycle, facing opposite the direction of traffic. It appears that he is having a conversation with the motorcyclist and a couple of pedestrians. They are blocking the crosswalk.
At 2:49, a motorist stops in the roundabout to yield to a bicyclist who does not cross, but instead turns right. The bicyclist gives a right-turn signal, but too late for the motorist to react, and in any case, a prudent motorist would not risk that the bicyclist would go straight even though signaling. The design of the roundabout does not make the bicyclist’s intentions obvious.
At 2:58, a bus barely outpaces a bicyclist through the roundabout. The bicyclist turns right, but the bus driver has no way to know that he will. The bus driver is either very highly skilled at judging the bicyclist’s speed, or reckless. The bicyclist would have had to yield to the bus if going slightly faster and continuing around the roundabout.
Starting at 3:00, several bicyclists enter traveling the wrong way on the bikeway or sidewalk. Some turn right but others pass close to a doorway which a pedestrian has just exited, and a blind corner, and cross from right to left in the crosswalk or bikeway. An articulated bus enters the roundabout and these bicyclists pass behind it. Other bicyclists traveling counterclockwise around the roundabout will have to yield to the long bus, though this occurs outside the field of view of the video.
At 3:45, bicyclists share the bikeway around the roundabout with a skateboarder and motor-scooter rider.
Almost all the bicyclists are pedaling about 40 rpm. At thsi cadence, it is possible to produce enough power to ride only slowly, and it is not possible ot accelerate smartly.
Here’s a roundabout where bicyclists go around square corners: http://goo.gl/maps/lxfc2
And a little roundabout with advisory bike lanes at some of the entrances: http://goo.gl/maps/HK908
In the so-called “shared space” roundabout in Drachten, cyclists share space with pedestrians. The meaning of the term “shared space” is very different here from its more usual meaning, that motorists, bicyclists and pedestrians all operate in the same space. In the Drachten roundabout, bicyclists and pedestrians share space — as on shared-use paths in the USA — but are strictly separated from motor traffic except in crossings, as in the other Dutch roundabouts. The space around the margins of the Drachten roundabout also serves as a pedestrian plaza.
I’m poking around in YouTube and Google maps. Here’s a roundabout in YouTube — http://www.youtube.com/watch?v=EXUF97p8fXQI — location not given, as is usual in such promotions, but I found it in Google Maps by searching on the name of one of the businesses nearby: http://goo.gl/maps/Jd2ED. A special feature made the roundabout practical: the buildings are set far back at a 45-degree angle on each corner. The circular bikeway around the outside makes it possible for motorists to see cyclists in order to yield (though motorists don’t always, as the video shows) and greatly adds to space requirements, which already are large for a roundabout. There wouldn’t be room for such a roundabout at many urban intersections.
Here’s a blog post which includes the video just described and others of the same roundabout, and describes different types of Dutch roundabouts. http://bicycledutch.wordpress.com/2013/05/09/a-modern-amsterdam-roundabout/
Another roundabout in Amsterdam is of the spiraling Turbo Roundabout design, with a path close around the outside and scary sight lines which place a cyclist too far to the right to be in view of a motorist exiting the roundabout: http://goo.gl/maps/fQybJ and street view, http://goo.gl/maps/LU1ww . Traffic signals have been placed at the exits to mitigate these conflicts. This is a triple roundabout with a tramway going around the inside, also requiring traffic signals.
The left and center roundabouts in this overhead view, http://goo.gl/maps/Q3jIy also are of the bikeway-around-the-outside type: but the rightmost roundabout, in a wooded area, is of the newer type.
Dutch roundabouts are of several types for motor traffic, but the major difference for bicyclists is whether they travel around the outside of the roundabout, or there are grade separations. There are no examples like the small modern roundabouts and neighborhood traffic circles in the USA, where bicyclists share the roadway with motor vehicles.
Here is an example of grade separation: https://bicycledutch.wordpress.com/2011/05/26/multi-level-roundabout-the-safest-solution-for-a-junction/
And here is a showcase example of grade separation — replacing an installation much like the one shown in the first video embedded in this post : https://bicycledutch.wordpress.com/2012/08/23/spectacular-new-floating-cycle-roundabout/
Roundabouts are expensive and take up a lot of space. Many of the promotions we are seeing of Dutch facilities ignore these limitations and the compromises they exact and/or celebrate the newest and most impressive examples.