[metric10]

It could also just pull over on to the shoulder and activate the hazard lights. It'll probably also sound an alarm in the cabin.

[cookingrobot]

Stopped on a shoulder is quite dangerous. Just staying driving seems better.

[metric10]

With an unconscious and unresponsive driver? Are you nuts?

EDIT: I have seen cars stopped on shoulders all the time. It may be dangerous compared to a parking lot, but this is an emergency situation. The driver is incapacitated and may need medical attention. I'll add that it should do more then run the hazard lights, it should dial 911. To keep driving means the car will run unattended for 200+ miles until the battery runs out.

[cookingrobot]

Not really an unresponsive driver - more like an unresponsive passenger. I bet a lot of people will fall asleep while being driven around.