I came here to say that largely excluding cars from city centers, along with a lot of other walkability/pro-socialization/human-scale-architecture changes is probably critical to reviving vibrant cities as they used to exist. Probably even better because there wouldn't be the problem of all the horse-poop. I genuinely think that this is the key to a new golden age of cities.
So, on largely removing cars from cities, I'm with you.
But seeing this top post about totally banning cars is absurd, even at the $1/mile proposal, and I'm all for radical steps to reduce climate change. You may have a zero mile telecommute, but most people have to move to where they work. Outside of the cities, a bike isn't even practical. I have a 25mi commute to my office, my spouse 35mi in the opposite direction. I even looked into a motorcycle for it's better mileage and smaller carbon footprint, but rejected it for too dangerous (& I've won championships in DH ski racing and sportscar racing). And I'm not even that rural -- others have longer daily commutes.
Unless you've got another system that can transport this scale of people to this scale of locations, your proposal just sounds like an out-of-touch elitest. The key point here is both the last mile problem, and the centralized maintenance problem. Look at the massive commuter transport systems of Boston and NY areas. They are a rolling disaster, almost terminally unreliable, and yet most of the riders still need cars to get to the train station. The build-out to get everyone withing a mile walk of a train station would be insane, even if eminent domain weren't an issue.