Robotic cars and information technology make the big cities obsolete. Global commerce will be easier. You can buy e.g. electronics from Amazon and get it delivered to your home. No need to go to market place at the city center as it were when these ideas emerged.
Robotic taxis and robotic cargo vans will replace trains, metros, buses and trucks because they have superior schedules as cars do nowadays. Using larger areas instead building higher will be the way.