The courts will decide
Google and technology will not decide the viability of driver less vehicles. The courts will. What happens when the first child jumping out into the road is killed? Cue the lawyers. It will go to trial and the courts will have to decide who the defendant(s) are. It's likely that they will just ban that type of vehicle as surely as Segways are banned in Europe.
BMW tried a similar "advancement" when they brought out that weird motorbike with a fully surround roll cage. The idea that you wear a safety harness and have a roll cage might mean that you don't have to wear a safety helmet, thus making a motorbike more appealing. Unfortunately, the law says that on all two wheeled vehicles the driver has to wear a helmet. The project was cancelled.