Uh, officer, my computer crashed...
Consider a future where these cars are proved to have a much lower accident rate than people, what then? Does society allow them? Does society REQUIRE them??
And what about liability? Accidents will still occur. With human drivers the blame is clearly with the human (usually), but with a robo-crash the blame is less clear. Will survivors of the deceased get to sue the car maker every time it happens, despite the proven superior safety factor of such cars? " Your honor, my clients placed their safety and very lives in the hands of this companys' product, and that trust was unforgivably violated."
I don't see robo cars EVER being accepted, simply because it would expose the makers to enevitable ruin, unless they became universal and required, with shield laws for the car makers in place. That would require everyone to give up their personally controlled cars. Ain't gonna happen.