Much is sometimes made of the requirement for cities to have a high population density in order to encourage cycling. It is said that it is essential for populations to live in densely packed areas to keep journey distances short before people will take to cycling.
Looking at the behaviour of the Dutch, who cycle more than the people of any other country, this seems to be a flawed suggestion. Or at least an over-simplification.
It is true that the population density of the Netherlands as a whole is quite high. There are nearly 400 people per square km in this country. Much higher than the 32 per square km that you find in the USA. However, whole country size scales don't really have much to do with the journeys that most people make on a daily basis.
Let's try this with densities of provinces or states, and cities within them. Assen is the capital of the province of Drenthe. This province has the lowest population density in the country, with 183 people per square kilometre. The capital of Drenthe is Assen, which has an area of 83 square km and 784 people per square km.
Five US states are denser in population than Drenthe. New Jersey, Rhode Island, Massachusetts, Connecticut and Maryland all have higher densities, New Jersey's population density is higher than that of the Netherlands as a whole. Delaware has the closest density to Drenthe, at 170 per square km. The capital of Delaware is a small city called Dover home of just 35000 people spread across 58 square km - which makes 617 people per square km.
These figures are really not so different to those for Assen. Assen's population makes 41% of all journeys by bike. Does anyone know the cycling rate of Dover ? Would it be reasonable to assume it's somewhat lower than Assen ?
Or look at the bigger cities. Los Angeles has over 3000 people per square km, but just 0.9% of commutes are by bike. New York has over 10000 people per square km. That's more than twice the population density of Amsterdam, but while 38% of all journeys in Amsterdam are by bike, only 0.6% of commutes are by bike in New York (which amazingly is still enough to be in sixth place amongst large American cities).
The same is also true of Devon in Delaware. Take a look at high school parking in Delaware and compare it with high school parking in Assen. Would it be conceivable for an American school to hold a triathlon as my daughter's school did here in Assen, telling the students to ride their bikes unaccompanied to a swimming pool at a sports centre 20 km away ?
It's quite mind-boggling just how little Americans cycle. However, it's also quite obvious why. Infrastructure has been designed over decades in such a way that it excludes cyclists. The photo was taken in the 1950s in Los Angeles.
Does where you live look like an inviting place to cycle ? Driving is the norm in many places because the infrastructure is designed around the car and it makes driving appear to be the only reasonable option. You see cars and car centric infrastructure almost anywhere that you randomly drop the Google Street View man in the USA. Whereas you've a good chance of getting cycling infrastructure and cyclists in street view scenes in the Netherlands.
It's perhaps interesting to note that the highest cycling rates in much of the Netherlands are actually in the North of the country, in the least densely populated areas, where journey lengths are often a bit longer. It's not population density which really makes the difference in cycling rates, but infrastructure which makes cycling into an obvious option. It has to be the most convenient, pleasant and safe way to get about. That's why 93% of the Dutch population ride a bike at least once a week.
There are many other excuses for why populations of other countries don't cycle.
I featured that photo at the top before. It's what Los Angeles already looked like in the 1950s. Roads like this are a large part of why people would choose not to cycle.