California regulators on Thursday approved an expansion that will allow two rival robotaxi services to operate throughout San Francisco at all hours, despite safety worries spurred by recurring problems with unexpected stops and other erratic behavior that resulted in unmanned vehicles blocking traffic, including emergency vehicles.

The state’s Public Utilities Commission voted to approve rival services from Cruise and Waymo to operate around-the-clock service. It will make San Francisco first major U.S. city with two fleets of driverless vehicles competing for passengers against ride-hailing and taxi services dependent on humans to operate the cars.

It is a distinction that San Francisco officials didn’t want, largely because of the headaches that Cruise and Waymo have been causing in the city while testing their robotaxis on a restricted basis during the past year.