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| The safe roundabout design for cyclists looks like this. Please read my previous blog post and watch the accompanying video as both of those describe the features of this design |
Now on with the new content:
Dangerous roundabout designs are a continuing issue in the Netherlands
Data from the Smart Traffic Accident Reporting system has been used to create a map which shows the most dangerous roundabouts in the Netherlands. I've picked out below some of the Dutch cities which I've written about before and shown how they rate for roundabout safety. There's a colour code in use. Roundabouts which have caused no problems are not shown, roundabouts with a yellow dot have seen a small number of collisions, orange dots are worse and red dots are the worst locations of all. The colour code doesn't tell whether collisions resulted in injuries.
The outcome is obvious. Every city in the Netherlands which uses the dangerous cycle priority roundabout design, regardless of the details of how their roundabouts are built, has a heightened rate of injury of cyclists. To give a point of comparison, first consider Assen, which has only the safe roundabout design:
Assen
Groningen
Zwolle
Zwolle's population is 125000 which makes just under twice the size of Assen. This city also uses the dangerous design of roundabout and again you see orange and red dots where many crashes have occurred. 105 crashes resulted in 37 people being hospitalized at the roundabouts in Zwolle between 2014 and 2017. Three years ago I identified one of Zwolle's roundabouts as the most dangerous place in the city for cyclists and it's highlighted on the map above having caused three more injuries. Crash rate: 1:4800, injury rate: 1:13500. One in every 13500 people in Zwolle is hospitalized each year by Zwolle's roundabouts.
Please read a more recent update about the danger of the roundabouts in Zwolle. Zwolle went to the effort of rebuilding roundabouts but they chose a different unsafe design to replace the unsafe design they already had. As a result, even the local government of the city has had to admit that three of the top ten most dangerous places in the city for cyclists are roundabouts.
's-Hertogenbosch
The population of 's-Hertogenbosch's 152000, which makes it about two and half times the size of Assen. The city uses the dangerous design of roundabout and they caused 105 crashes with 34 injuries over the 2014-2017 period. Three years ago I assessed two of the two of Den Bosch's roundabotus as being the most dangerous places for cyclists in the whole city and one of those is highlighted above showing the that it has caused three more injuries. Crash rate: 1:5800, Injury rate: 1:17900. One in every 17900 people is hospitalized each year in Den Bosch each year due to the roundabout designs used.
Enschede
Middelburg
Drachten
More Shared Space roundabouts ?
Given the poor track record of Shared Space in general and the poor track record of the Shared Space roundabout in Drachten, you might think people would steer clear of the concept. But that's not happening: A new shared space roundabout was recently built in Winschoten and it's got such a bad record already that it was recently recognized as the most dangerous roundabout in the entire country with just one location having caused 13 crashes and 3 injuries. Winschoten's population is only about 18000 but this roundabout is so bad on its own that we get a crash rate of 1:5500 and an injury rate of 1:24000 per year for the population while ignoring everything else in Winschoten.
Are we designing for efficiency and safety ?
The crash and injury rates quoted for each city above are a primitive way of making a comparison, simply dividing the population by the average annual rates of crashes and injuries without any other factors, but nevertheless, the point as does all the other data, towards Assen's roundabouts being amongst the very safest in the Netherlands. So why isn't the rest of the country copying this safe design ?
We shouldn't be surprised by this result. It was predicted 13 years ago.
It's been known for many years that the design of roundabouts which gives cyclists priority over motor vehicles around the edge of the roundabout, relying upon drivers always to spot a cyclist who might emerge quickly from a blind spot and assuming that all drivers pay attention to ensure the safety of others as they drive, inevitably results in more injuries. In 2005 the extra injuries resulting from this design were estimated as 52-73 people requiring hospitalization (in-patient treatment) each year.
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| Roundabouts in the Netherlands over time |
If more than a hundred people per year are being injured due to a choice of roundabout design when a much safer design which is proven and already in wide use could be adopted, there needs to be some other justification for the unsafe design. Typically, people claim that it's more efficient for cyclists to have priority, but unfortunately the "priority" is merely part of the name of the design and not any proven effect. In reality you can't ride around a priority roundabout as quickly as you can ride over the safe design because you have to be quite cautious when you're relying on others always to look out for you. In fact, many "priority" roundabouts are quite unpleasant and inefficient for cyclists because we are forced to cross more lanes, which means slowing considerably and repeatedly checking whether drivers approaching in both directions who are supposed to have noticed us actually will give way to us, and the much tighter corners on the priority design often cause trouble.
Are we just adopting the "priority" design because that word sounds good ?
A few days ago I rode through a particularly poor recently built example of a "priority" roundabout, one which bizarrely has been held up as a good example locally. This morning I went back to the location especially to make a video showing how extraordinarily inefficient a "priority" roundabout can be, and how it can expose the cyclist to needless extra danger:
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| Not all of the poor features of this roundabout and surrounding infrastructure are included in the video. This gentleman clearly had ridden on the "wrong" side of the road, treating a narrow unidirectional cycle-path as bidirectional. People do that if the infrastructure makes doing the wrong thing more convenient than doing the right thing. Once you reach a priority roundabout when travelling in the wrong direction, all bets are off for safety. |
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| If I had made a return trip through the roundabout in the video I would have ridden here. This skips the indirection to the other side of the road, but instead riders have to cross three lanes of traffic, the first of which is a bus lane, and pass over two islands, neither of which is wide enough to offer safety even to a child's bike. I suspect that in reality few people go all the way around in the video so there will be many people riding in the wrong direction here. That is far more dangerous because they'll be relying upon drivers looking in both directions at once across three lanes for their safety and they haven't got any refuge to hide in. |
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| Stills from the video above. How can anyone in any seriousness claim that the "priority" roundabout on the left, which requires cyclists travelling South to North to turn sharply and cross six lanes of traffic to go all the way around the roundabout, is safer or more convenient than the one on the right where cyclists cross two lanes of traffic in a straight line with good sight-lines ? |
The safe design is well established and has a proven track record. It also is naturally resistant to error in implementation due to imperfect copying of the design, making an ideal basis for other countries to create their own safe roundabout designs for cyclists.
The "priority" design is proven to cause a significant level of injury to cyclists in the Netherlands and even here is misinterpreted quite often in such a way that it is more dangerous than it need be and causes significant inconvenience to cyclists, as shown in the video above.
The roundabout design which should be copied by countries outside the Netherlands is therefore the safe roundabout design. Copy what is proven to work, not merely anything that is "Dutch".
On our study tours we demonstrate the difference that good infrastructure makes. Roundabout designs are included.
Danish Study
A new study from Denmark provides more supportive evidence. In particular (from the Abstract): "Single-lane roundabouts with separate cycle paths, where cyclists must yield to motorists entering or exiting the roundabout, are safer than roundabouts with cycle lanes." It doesn't matter which country they are inplemented in: the principles of safe roundabout design remain the same.
Update December 2019 - new Dutch study
A new Dutch study which analyzed the safety of all roundabouts in the Netherlands has shown that four times as many cyclists are injured on roundabouts where cyclists have priority as on those where they do not. The study further notes that roundabouts with bidirectional cycle-paths are safer than those with unidirectional cycle-paths. It is of course the case that almost all of the safe without priority roundabouts use bidirectional cycle-paths while these are less common (and less safe) on the with priority roundabouts, so that's further supporting evidence
