The problem is you need to be able to get to that area before you can eliminate cars. If you are not careful you can kill an area because the people who used to drive there cannot anymore and so they just go elsewhere. If you already have a lot of people arriving by something other than cars, then you can replace the parking lot with something else and make better use of the space, but most areas don't have that advantage.
Building such places is not easy where they don't already exist. It isn't impossible, but you need to start there.