dr david carroll, thank you so much forjoining us. a pleasure, thank you. city voted to allow them to operate 2a hours a day. but some people are determined to get them off the roads. james clayton has the story. one of the things that surprises many visitors when they arrive in san francisco are these things — driverless robo—taxis. they're all over the city. this is me ordering one on my phone. one minute away, there's a cab just around the corner. but before i could even get in, a member of the public approached us with a warning. i think you're unsafe, because i saw a guy that was in the crosswalk at night, almost got hit by it. well, thank you very much, sir, cheers. not exactly the ideal thing to hearjust before you get into a cab with no driver. i've been in these cars a few times now and it never changes. it's always totally surreal. it always feels nerve—racking when you first start, and it's really surprising how quickly itjust becomes totally normal. but the first few sort of roads you come across, t—junctions, you're kind of always slightly appr