Seems pretty obvious to me they would be overall better and safer than humans!
People mentally compare them to a perfect human driver, but in reality far too many human drivers are very far from perfect and they are driving on our roads as well.
I think we'll get some headline horror crashes that make the doomsayers proclaim "I told you so!" but actually the number of crashes will go way down. And even the horror crashes probably will only be reported widely because they are robot drivers. Human driver crashes are hardly reported outside local news at all these days unless they are multi-car, criminal chases or block a motorway for hours.