"In Europe, the cities were originally built and designed long before automobiles, trains, and streetcars and the resulting layout results in a denser environments where mass transit works better."
Bucharest (Romania's capital) was a typical European city like that you're describing, but it was heavily reshaped (especially in the 1977 quake event) and is continuously worked on both in access infrastructure (extending and improving) and real estate development, and they somehow manage to keep it both automobile friendly and convenient for the the rest. The automobile possession here gets more of a whim than a necessity, as the public transportation covers literally everything, even at night! This isn't that much a mater of how things tend to fit naturally, as it is cultural. I get the impression that in USA they go lengths to keep things in a state where you have to need a car.