reporter: cruise says its mission is to work with cities and make it safer. there s over 40,000 fatalities happening on the roads in the united states. we have driven over 3 million driverless miles. and we have had no life-threatening injuries or fatalities. need to buckle is the same as always. reporter: waymo declined an interview with cnn and said it s proud of its driving record and creates better performance than a reference model of a human driver. avs aren t just in san francisco. cruise is already operating in austin, texas, and los angeles, too. chief nickelson has a warning for other cities. pay attention. get on board. get ahead of this. because it s coming your way. and i don t want them to have happen to them what has happened
Caused by cars with no one in the driver s seat. there s like one, two, three, four cruise cars blocking. no one can get through. reporter: these driverless cabs stalled for half an hour outside the outside lands music festival. in the last two weeks, incidents involving autonomous vehicles have spiked after a regulatory agency approved gm s cruise and google s waymo to expand their driverless car services in san francisco. hello. i mean, i couldn t have predicted it any better. i don t think any of us could. reporter: san francisco city leaders including fire chief janine nickelson were outspoken about safety concerns, requesting more testing and regulations for the innovative but potentially dangerous technology. just days after california s public utility commission voted to allow cruise and waymo to roll out more cars in the city at expanded times, a cruise car