Suburbs will always be suburbs. Maybe not a bad thing. With Hyperloops and 150 mph autonomous cars running in pelotons on dedicated freeway lanes one can live in the burbs and work in cities. The Pittsburgh-Columbus-Chicago Hyperloop demonstration proposal provides a 40 minute commute from Columbus to either Chicago or Pittsburgh. At 150 MPH Grass Valley-Nevada City is less than an hour from SF.
Those few that like urban living will have plenty of it at reasonable prices once any burb is less than an hour away from city jobs by hyperloop or 150-200 mph freeway lanes. Ford, General Motors, and their foreign competitors will insure that the US will -always glorify suburban living with the car and the mortgaged house as the primary status symbols. Huge high-rise garages for autonomous cars will grow like weeds at transit centers. Get out of your car at the transit interface nearest your job, tell the car when you will be back and tell it to go park itself.
In the burbs the autonomous car will drop you at the garage over the freeway at the regional urban center, probably still low rise and driverless taxis will shuttle you to your entertainment center and community place.