[rumanator]

> Then more people live in the suburbs, but you need a car to get from the suburbs to the city.

Your assertion ignores the fact that network coverage means nothing if the time to traverse the network just to get from point A to point B is much more expensive, time-wise and economically, than simply using personal transportation to get to where you want to go.

[AnthonyMouse]

That isn't inherently true in the city center. If you have the population density to run subways every ten minutes that aren't subject to traffic jams, you can get from one part of the city center to another faster on a subway than in a car. But that only works if both of your endpoints are on a subway line, which requires more people to live in the city center than they currently do.