In a statement on Dec. 13 about the testing of autonomous vehicles, the Department of Motor Vehicles said: “We have a permitting process in place to ensure public safety as this technology is being tested. Twenty manufacturers have already obtained permits to test hundreds of cars on California roads. Uber shall do the same.”

Nonetheless, as recently as Friday, Uber remained defiant. It said that it had no intention of ending its test and that its self-driving cars were still on the road and picking up passengers.

Uber officials contended that under the letter of California law, the company did not need a permit because the Motor Vehicles Department defined autonomous vehicles as those that drive “without the active physical control or monitoring of a natural person.”

Uber said its modified, self-driving Volvo XC90s required human oversight, and therefore did not fit California’s definition of an autonomous vehicle. Companies such as Google and Tesla Motors have all gotten such permits.

“This rule just doesn’t apply to us,” Anthony Levandowski, vice president of Uber’s advanced technologies group, said in a conference call with reporters last week. “You don’t need to wear a belt and suspenders and whatever else if you’re wearing a dress.”