/u/oddlysaneconsidering since you deleted your comment mid-reply.

Heres my response anyways:

The idea of mass transit is to reduce the number of vehicles on the road. It is better to have larger vehicles to move more people to general areas of interest instead of many smaller vehicles moving them to specific spots. Road wear, emissions, etc. all increase with more cars on the roads. Isn't that the whole point?

Autonomous vehicles would provide a more reliable service. Until the vehicles become self aware (Skynet) and/or turn on people (Maximum Overdrive), it would take fewer people to operate the system and yes, there is less risk of threats to shutting the system down.

Now, you typically come running to the defence of anything against the public sector unions defending it with "what, you don't want people having good jobs?", so I'm not going down that road with you.

The point is, if a transit system could be autonomous, it would be more reliable and better economically for the region/city.