[jacobolus]

It’s true that Manhattan is considerably denser than Copenhagen. Manhattan probably needs more/different transportation infrastructure than Copenhagen does to cope effectively with the density: more public transit, less automobiles.

The population density of Copenhagen is comparable to the density of Queens.

There is also a significant cultural difference. In the US, the biggest bike commuters are high school and college students. In some countries, bicycles are used by a broad swath of the public.