So, all Jack the Ripper needs is to put a flashing light on his car and he can force his victims to a stop? No thanks.
Hell, it's not unheard of for actual police officers to engage in kidnapping, rape, and murder - if you suspect such a situation, they should NOT be able to trivially disable your vehicle.
Sure, it should automatically respond to police signals just as a conscientious driver would. But you should also be able to override that behavior, just as a driver with a sense of self-preservation sometimes must.
Meanwhile, an unconscious occupant would seem to me to be one of the points of an automated vehicle. Any automated vehicle which needs me to continue to pay attention to the road in case of emergency is a horrible danger to everyone else, because passengers won't do so reliably. And if I don't have to pay attention to the road, then I may as well play video games, take a nap, etc. Just like if I had a chauffeur. You wouldn't pull over a limo because the passengers were unconscious would you?
That is the case now. You are obligated to pull over. Now... I agree with a manual override. If Jack the ripper starts walking towards the car, then I would like to be able to hit a button and drive away. Or if you really feel unsafe where the car wants to pull over, then similarly I would want a manual override.
I agree that having an automated car will actually save lives where now if the driver has a medical issue the likely outcome is a high speed collision which endangers even more lives. But if the passenger has truly had a medical issue and can't stop the car then it would be good to have the ability to pull the car over. Again, manual override should take precedence. But if the person is on the phone with 911 and passes out the car should be capable of getting pulled over by a single patrol car. Something as simple as a directive to slow down and pull over when a car with flashing lights is behind you.