Cars can serve dense neighborhoods if they are more self contained. If you can architect things so that people mostly walk or bike to everything then the car is

Cars can serve dense neighborhoods if they are more self contained. If you can architect things so that people mostly walk or bike to everything then the car is only for special trips. In such a world public transit is only necessary for major arterial commuting. Self driving cabs can also transfer people between these arteries to maximize throughout. But milk route busses and subways stopping every other block will be unnecessary. Getting to this world would require much more communal space and stronger neighborhoods with more of a cultural center of gravity so you didn't have people flitting all over the city in rabdom directions in desperate attempts to find a place to fit in socially and professionally. Imagine small towns, packed as densely as a big city. An arterial subway like San Francisco's is adequate for that.