Uber's self-driving cars will keep ferrying passengers around San Francisco, the ride-hailing company said Friday a few hours before state prosecutors threatened to haul Uber before a judge if the service is not suspended immediately.
In a sharply worded letter, attorneys with the California's Department of Justice demanded that Uber get a special state permit if it wants to continue. If not, "the attorney general will seek injunctive and other appropriate relief," according to the letter.
Though there was no deadline in the letter, a spokeswoman for California transportation regulators, Melissa Figueroa, told The Associated Press in a text that the state would take action "early next week" if Uber doesn't comply.
Uber began the pilot project Wednesday with a few Volvo SUVs that are tricked out with a suite of sensors allowing them to steer, brake and accelerate. A person sits behind the wheel, just in case.
Uber posted the announcement to Twitter.
Officials with Uber and the state have talked several times this week after the state Department of Motor Vehicles issued a similar legal threat. The leader of the company's self-driving program, Anthony Levandowski, described those as "frank conversations" which left him unswayed.
State lawyers insist that Uber's cars are "autonomous vehicles" which need the permit to ply public roads.
Levandowski said he respectfully disagrees, arguing Uber does not require the permit that 20 other companies testing the technology in California have gotten because the Volvos have backup drivers behind the wheel monitoring the cars.
That means the Volvos are not "autonomous vehicles" under the state's definition, he argued.
Levandowski likened the Volvos' abilities to those of Tesla cars that have the Autopilot feature which allows them to steer without a person touching the wheel and to brake and accelerate without a person touching the pedals. He questioned why the thousands of Teslas on California roads don't need a permit if Uber's cars do.
San Francisco's mayor has sided with the state. And a consumer advocacy group suggested that the state should do more than force Uber to stop.
"We believe their activity is a criminal offense under the motor vehicle code, punishable with up to six months in jail," John Simpson of the group Consumer Watchdog said in a written statement. "CEO Travis Kalanick should be arrested immediately."
But in a sign of the level of interest in the technology, the mayor of Beverly Hills on Friday voiced his support for Uber testing without the state permit.
(The Associated Press contributed to this report)
WATCH | Inside a self-driving car