Not necessarily. Cars still use a large amount of land area per person, even if they're self driving and don't need many car parks (I disagree with that last part though, considering commute patterns).
Take a look at http://carfree.com/ for a good overview of what could be done with public transport, as well as all of the unseen issues with car use.
Take a look at http://carfree.com/ for a good overview of what could be done with public transport, as well as all of the unseen issues with car use.