California police officers conducting a grant-funded DUI enforcement operation in San Bruno had an unusual encounter last week when they pulled over a driverless Waymo taxi for making an illegal U-turn, authorities said.The incident occurred at a traffic light on Friday evening. The autonomous vehicle committed the infraction in front of officers, who quickly realised there was no one behind the wheel. “That’s right… No driver, no hands, no clue,” the San Bruno Police Department wrote on social media, adding that they contacted Waymo to report the glitch.Since the vehicle had no human operator, police could not issue a traditional citation, joking that their ticket books “don’t have a box for ‘robot’”.Waymo, which operates self-driving taxis in cities including San Francisco, Los Angeles, Phoenix, Austin, and Atlanta, said in a statement that the Waymo Driver is “designed to respect the rules of the road” and that the company is reviewing the incident to improve road safety, according to CBS News.The encounter highlights challenges in regulating autonomous vehicles. California passed a law last year allowing officers to issue a “notice of noncompliance” if a driverless car breaks traffic rules, set to take effect in July 2026. The law also requires companies to provide a hotline for first responders and mandates that vehicles respond within two minutes to move out of emergency zones.San Bruno police said the legislation will allow officers to hold companies accountable when autonomous cars drive recklessly. “Whether it’s drivers, passengers, or even driverless cars, we’ll continue to do our part to keep San Bruno’s streets safe,” the department said.Waymo has faced previous issues with its vehicles, including a recall of over 1,200 cars earlier this year due to software problems that caused collisions with stationary objects. The National Highway Traffic Safety Administration has also investigated the company after receiving multiple reports of erratic vehicle behaviour.