You can't even get a (vice) presidential motorcade through the streets of San Francisco these days without tripping over a self-driving taxi.Democratic presidential nominee and Vice President Kamala Harris was back in hometown of SF this weekend for a fundraiser, and she landed Friday night ahead of the Saturday event.Harris's motorcade traveled from SFO to the Fairmont Hotel in San Francisco Friday night, and as ABC7 reports, not one but two self-driving Waymos got in the way of the motorcade before it could make it to the hotel. In the second of those incidents, which happened atop Nob Hill on California Street, just as the motorcade was pulling up to the Fairmont, the Waymo got stuck trying to make a U-turn in the middle of the street, and a San Francisco police officer had to take control of the car and drive it out of the way when it became disabled.Waymo has not yet made any public comment about the incident.Waymo's autonomous vehicles, while sometimes a nuisance, have yet to be involved in any serious collisions in San Francisco, unlike competitor Cruise, which continues to wait for its license to operate in SF un-suspended. Waymo's vehicles have, though, reportedly had a number of near-misses with school crossing guards and children in crosswalks in the city, which is no doubt something the company has been working to correct.Harris ultimately made it to her hotel, ahead of Saturday's fundraiser at the Palace of Fine Arts. Tickets for the event were priced between $500 and $2,800.