For the 1000th time here, even extremely well developed public transport by US standards and various financial punishments for owning cars is simply not enough for people to drop them, the convenience is simply too high.

Look at Switzerland, it has all you want - one of the best rail networks in the world, its tiny, rest of public transport is as good as western Europe can get yet... folks still keep buying new cars, highways are getting fuller every year.

Maybe some AI driven community (or even private fleet) of shared cars to be hailed in Uber style on demand would work, reducing number of cars overall and the need to own personal one(s). Not there yet.

I don't think anyone envisions having no cars; public transportation make it so we don't need cars, and other nudges make it so we have fewer cars than we would otherwise have.