There could be a combination of the two. Say, six shuttles with one human watching camera feeds and monitoring for problems so they can contact the right people

There could be a combination of the two. Say, six shuttles with one human watching camera feeds and monitoring for problems so they can contact the right people. That would help deal with corner situations like crime/vandalism and also service issues ("Hey dude, this guy is sick and just threw up" or "hey I think you ran over something the tire is flat").