Most people couldn't perceive the world without mass public transportation means like trains, buses, shuttles because their minds stay with the world they grew up to see.
With fully self-driving vehicles, current roads in cities are enough to support 50-75% less automobiles. There'll be no congestions at all. Subway/Lightrails will prove to be a waste of money in 30 years. A lot of empty lanes can be converted to bike/running lanes for people to exercise and enjoy.
Truth is only in the grasp of few, indeed.