Actually, I was just joking. Maybe I watch too much scifi.
I think it's a great idea to develop the technology, however I'm not sure why we need (or why there would ever be viable market for) robot cars and/or robot drivers. Aren't there enough people out of work already?
To comment on a few of your points:
It's one thing to put a plane in the open sky on autopilot for a while, but auto traffic is another thing. Lots of variables.
They're on a track.
Doing very limited, repetitive tasks.
A big if. But assuming that acceptable robot driving technology is someday developed, who's going to be able to afford to buy it? Would it put a certain segment of the population out of work?
This assumes that robot cars/drivers are going to be implemented on a massive scale wrt individual vehicles.
A simpler solution to the problem of teen driving is to raise the driving age.