"Trains and buses are much more efficient at moving people than individual cars, even if they're self driving"
Dubious claim that needs evidence. I think you're underestimating the potential throughput gains from autonomy. As just one example, speed limits can probably be greatly increased when you take the realities of human reaction times out of the equation.
How much energy does it take to operate a train station or get people to the train station? What is the time and monetary cost spent getting to and from a train station and waiting on trains? How many NYC or Paris or Seoul subways run at 3am?
Can't speak for Paris or Seoul, but in NYC probably about helf the lines run 24/7. Of course, that's one of the reasons the system is so hard to maintain.
Dubious claim that needs evidence. I think you're underestimating the potential throughput gains from autonomy. As just one example, speed limits can probably be greatly increased when you take the realities of human reaction times out of the equation.