As usual, non-technical solutions are simpler than technical solutions. It would be good to build the economy around communities, where people can walk or cycle for work, shopping or leisure, rather than have specialised zones that people have to drive between (think Milton Keynes). This may mean reducing the scale of enterprises, but that works for us. Other aspects of reducing need are living closer to where we work, working from home and low-impact tourism, without flights.
With a global population heading towards 10 billion, there doesn’t really seem to be a way to have cars sustainably (unless you think that only certain privileged people should have them). In a world without cars, we’d have to reorganise ourselves so that most of what we need to do is within walking and cycling distance.