it's very doable, suburban sprawl costs local governments more to upkeep than it would to develop more dense housing. Just think of all the needless tarmac and intersections and carparks that need to be continually maintained. Not from the US but from what I understand, many, many young people over there want to live in apartments which are in mixed urban centres. There is a reason why they are so expensive right now.. The problem is lack of zoning for mixed low rise, and commercial. You don't need to drive 75 miles across the city if your work, shops, bars etc are a mile away. If zoning was changed, with improvements to public transport and road design (less lanes, no stroads, more pedestrianisation etc) US cities could change in a couple of decades.