i always assumed they had an ops center with live drivers ready to step in. seems the only sensible way to get started.
Such an intervention can (and will) simply kill passengers.
Insurance helps a bit, but does not recover from death.
that and their potential ability to do radio sensing to provide high resolution realtime maps of their environment.
It's not rational, of course: just knowing how much things regularily goes wrong in a low-level net makes me feel that way.