Having spent a little tiny bit of time in the Netherlands in both Amsterdam and The Hague, I suspect it's simply the combination of a flat landscape combined wi

Having spent a little tiny bit of time in the Netherlands in both Amsterdam and The Hague, I suspect it's simply the combination of a flat landscape combined with comfortable weather for strenuous outdoor activity and most people living in pre-car cities which are sized about right for pedestrian activities which fed into a virtuous cycle that both recognized these things and then built legal and physical infrastructure to support them, which in turn made cycling easier and more convenient and so on. It's very hard to conveniently cycle around many other cities due to not having one or more of the three foundations needed to kick off the cycle. Even in non-optimal cities, putting a cycling infrastructure in place doesn't necessarily result in lots of cyclists and doesn't necessarily determine cycle usage. For example, the entire U.S. state of Florida might be an ideal biking location. It's flat after all, but most of the state was built to support cars, and the weather can be mighty hot. It also has the highest cyclist fatality rate in the U.S. with Orlando specifically often called out as one of the worst cities in the world to cycle in.