Monday, 28 February 2011
This is another of those myths and excuses that I've covered before, but just keeps on coming up. i.e. that the Netherlands has a high rate of cycling because Dutch cities are especially dense. Some campaigners make a lot of wanting where they live to be more dense in order to try to achieve a higher cycling rate. Actually, there is not much of a correlation between cycling rate and density.
As you'll see in the plot above, it isn't true that cities with the highest population densities have the highest cycling rates. Rather, you'll find that Dutch and Danish cities have the highest cycling rates, whatever their density happens to be, because cycling in them there is a more pleasant experience because these cities have invested in cycling infrastructure in order to make it pleasant. Subjective safety is very important.
The belief that the Dutch live in remarkably highly densely populated cities is just a myth. Assen, where we live, has just 780 people per square km. That's not only significantly less dense than New York, but also than relatively spread out American cities such as Portland (1655 people per square km).
New York makes a great example. Over 10000 people live in each square km of what is a very compact city for its population, yet for all the recent hype about growing cycling, the cycling rate remains extraordinarily low by international standards: Just 0.6% of commutes are by bike. Conditions may be slowly improving, and it's a very good thing that they are, but it's still not yet a place to look to internationally as a success story. They're a long way from the point where all types of people feel safe to cycle for a large proportion of their journeys.
Much to my amusement, some Dutch people believe the same story about density. i.e. that they have relatively densely populated cities. I was once told this as part of a presentation about Groningen, the density of which is actually just 2300 people per square km. Even the capital of the country, Amsterdam, has just 3500 people per square km. The highest density city in the Netherlands is Den Haag with 5900 people per square km, but Den Haag does not have anything like the highest cycling modal share for a Dutch city. Quite the reverse, in fact, as in a presentation to us on a visit a few years back, the cycling rate there was described as "quite low".
To summarize, population density has little to do with cycling rate. Even within individual countries there is little correlation. You'll see that less densely populated Portland does better than more densely populated New York, that Cambridge does better than London, Bremen does better than Berlin, and that Groningen does better than Amsterdam.
At this point, it's traditional for some people to respond with comments about average journey distances being so much longer in whichever country they live in. However, I'm afraid that doesn't really hold water either. While the mean distance is skewed due to the maximum possible journey distances being greater, the median for everyday journeys does not vary as much as you might imagine. Even in the USA, every-day journey distances are limited by time more than by the actual distance and 40% of all journeys are under 2 miles in length. The longest journeys may not be practical by bike, but Americans rarely choose cycling as a mode of transport even for the shortest journeys.
By contrast, longer cycle journeys are easier to make in the Netherlands. We find this from our own experience. Places that seemed "too far to cycle to" in the UK are often closer together than we remember them being, and people make the same and longer distance journeys here by bike without a second thought.
The reason for the vastly higher rate of cycling in the Netherlands is not population density, but policy which support cycling, effective campaigning, and successful infrastructure design.
For those who prefer a scatter graph:
The cycling rates for cities with stars after their names are the lowest on my graph, but they're all actually exaggerated relative to the other cities in the list. For these cities I could find only figures for "commuters" and not for all journeys. That the local authorities should choose to publicise this figure instead of one for all journeys is itself an indication that you don't see a lot of school children, parents with children, or pensioners on the streets of these cities. Where there is a healthy cycling culture, commuters are a minority of cyclists.