Subways will remain in dense city centers because they offer capacity that cannot be matched with buses. Driver or no driver is irrelevant. Your argument probab

Subways will remain in dense city centers because they offer capacity that cannot be matched with buses. Driver or no driver is irrelevant. Your argument probably will hold true for regional trains and high speed trains, though. The travel time will be quite similar if you factor in the time to and from the railway stations.