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.
@jef also how dangerous to leave dangerous vehicles unattended on the road? IMO they should ticket the owners or the company who built the damned things. That would save lives.