Last week, Uber announced that it had expanded its self-driving pilot programme in the United States, bringing the project to San Francisco. Working together with Volvo, the transportation network operator has deployed a fleet of 11 Volvo XC90s in the city.

Following its announcement on the matter, the California Department of Motor Vehicles (DMV) stepped in by saying that the self-driving Volvos were illegal and asked the transportation network operator to cease operations and seek the necessary testing permit for autonomous vehicles, failing which the department would initiate legal action against it.

The DMV pointed out that 20 companies – including Ford, Google, Mercedes-Benz and Tesla – have been approved to test a total of 130 vehicles, and said the permit is required in part to protect public safety.

Now, in the latest development, the ride-sharing service is defying the order, saying that it has no intention of halting its test programme, and that its cars were still on the road. Not all the XC90s are being deployed to pick up and ferry passengers; a number are being utilised to log mapping and monitor research miles.

According to news reports, Uber says that its cars don’t need permits because the ruling defines autonomous vehicles as those that drive “without the active physical control or monitoring of a natural person,” and the company stated that its self-driving XC90s require human oversight, with a person in the driver’s seat, therefore not fitting the state’s definition of an autonomous vehicle.

The company added that the XC90s have two persons monitoring activities in each vehicle, in the driver and front passenger seat. When the vehicle is operating, the driver has his hands resting on the wheel at the 5 and 7 o’clock position to take over at a moment’s notice. It added that there was also a secondary set of controls on the passenger side, giving the operator in the seat access to the car should that be necessary.

As such, the rule didn’t apply to the company, Uber’s VP of advanced technologies group, Anthony Levandowski, said in a conference call with reporters. “You don’t need to wear a belt and suspenders and whatever else if you’re wearing a dress,” he stated.

Levandowski said that DMV’s decision-making process should be consistent across the types of vehicles on the road, adding that the company was not seeking to exploit some loophole in the law.

“The distinction between our self-driving Ubers and the autonomous vehicles described by California State law is not a legal nicety. It’s an important issue of principle about when companies can operate self-driving cars on the roads and the uneven application of statewide rules across very similar types of technology,” he said.