the safety record of the Google cars is nothing short of fantastic.
Says who? Google? Of course, they are completely unbiased.
Thing is, a universally accepted test of driving competence already exists: it's called getting a driver's license.
As soon as a robocar exists that can pass the standard driving test given in all states and provinces, day or night, and in all weather conditions, then I will believe that its safety record is "nothing short of fantastic".