[hibikir]

You are talking about something that has very little to do with the population density and zoning of an American midwestern suburb: What we mean is something like this, where having no car makes you a second class citizen.

https://goo.gl/maps/U5qhh

What you call a suburb is more like what in Spain are called 'ciudades dormitorio': Small towns with a much higher population density than the american suburb, and that have good communications with downtown. People live less than a mile away from a train station that drops them in a public transportation hub in downtown Madrid. It's still a suburb, but it has absolutely nothing to do with what an American describes.

[hammock]

They are called the same in English: bedroom town.