Where a train can move 20k+ people an hour in each direction, a standard road moves around 1k. Self driving cars will only make sense as chauffeur replacements

Where a train can move 20k+ people an hour in each direction, a standard road moves around 1k. Self driving cars will only make sense as chauffeur replacements for Uber, Lyft and Taxis, as even with a tripling in capacity, you'd still be wholly uncompetitive with rail. Nevermind the inefficiencies of enlarging roadways :P