Being as the travelling public have yet to accept driverless trains, this may be some way down the line.
Take trip on DLR - the front seats are quite popular and the conductors very chatty.
Isn't the problem with the current generation of UAVs that they can lose signal if banked too steeply, and that sometimes the pilots lose situational awareness?
Future UAVs would be more or less autonomous and free to make their own decisions within a set of parameters. This is a major topic of concern for Western countries.