They can do that now unless you are suggesting running them over as a solution.
No doubt we'll see people doing this, however. Because change is scary.
Just turn around? So the cars will be near spherical in design and with 4 wheel steering? Cool.
There are so many unresolved issues around self-driving cars, and the answer always seems to be "just do this", without any real solution to the problem as described. Self-driving vehicles may well be a good thing, but let's not stick our heads in the clouds and assume "it'll be okay".
Heck an accidental release of confetti would be an interesting experiment.
The cops would only be called if the car is blocked for several minutes or the passenger decides to do so. Nobody cares if the car has to brake for a few seconds and then continues driving as usual. We spend far more time at traffic lights anway.
By motorcycle
(I'm sorry, I could not resist. I tried.)
I would put the ratio of bad pedestrians to bad drivers at 1:1000.
I think these cars are going to work brilliantly in very polite and orderly places like Zurich, where everybody takes their turn and neither pedestrians nor bicyclists nor drivers feel put upon by the system. I have no idea how they are going to work here in America where we dump our mentally ill on the streets, and then don't give them sidewalks and crosswalks or any sense of dignity. I have a feeling it's going to work quite poorly.