I have a 40 foot driveway and a one-car garage. House was built in the 1950s, which I guess is the era of the one-car family.
Looking at my current transportation choices, this seems a bit silly. I should probably have a smaller lawn (or no) lawn if I didn't have a driveway to support extra cars. I probably also could replace the garage with a smaller shed in the back for tools and repair area.
What about your housing? Do you need drastically change when you don't have a car?