A human driver can certainly can be careless or dangerous, but in my experience this is not how blame is assigned in the case of a collision. It is assigned ba

A human driver can certainly can be careless or dangerous, but in my experience this is not how blame is assigned in the case of a collision. It is assigned based a failure to conform to very specific rules of the road - operating left of center (or right, depending on the country), failure to yield, etc. Human factors are taken into consideration, but there is certainly an existing framework for assigning responsibility that appears to be quite compatible with autonomous operators. I would suggest that the shared responsibility case would be the same as it is today - when both operators are in violation.