US cops pull over driverless car after illegal U-turn

Officers in San Bruno, California pulled over the Waymo driverless car on Friday night, but -- despite its flagrant law breaking -- had to let it go.

"Since there was no human driver, a ticket couldn't be issued," police in the city, south of San Francisco, said on social media.

"Our citation books don't have a box for 'robot.'"

Describing the situation as "a first" for law enforcement, the police department said they had spoken to Waymo about the problem.

"Officers... contacted the company to let them know about the 'glitch.'"

Waymo told AFP its autonomous driving system has been designed to obey the rules.

"We are looking into this situation and are committed to improving road safety through our ongoing learnings and experience," the company said.

Waymo operates fleets of driverless taxis in and around a small number of major US cities, including San Francisco and Los Angeles.

The vehicles -- white Jaguars equipped with an array of sensors -- navigate around known cityscapes using an onboard mapping and computing system.

Despite their unnerving appearance, with an empty front seat and a steering wheel that turns on its own, the vehicles have proved popular with passengers.