Remove the idea of "car" and think of auto-driven cubes with their own pathways within a city. Similar to subways, but can be above ground with covering. You don't need parking, streets, traffic signals, and a whole host of infrastructure is eradicated.

You go by behavior:

- I need to go to library, store (walk or bike) - I need to go a business or house (cube it) - I need to leave the city for long-distance travel (now we connect to mass-transit)