Supposedly, SFPD can't ticket misbehaving robocars because there's no driver to sign the ticket. I have come to believe that this interpretation is in error. Standard procedure when a driver won't sign a ticket is to arrest them and impound the vehicle. Just because the driver, meaning the person responsible for the driving, is not present, shouldn't change this.
Law enforcement could be given the ability to shut the robocab down. Nope. Stupid suggestion.