SAN FRANCISCO (Reuters) - Uber Technologies Inc on Thursday removed its self-driving test cars from California and put them on trucks bound for Arizona, shuttering the autonomous vehicle project in its home state after a week-long battle with regulators.

A photo illustration shows the Uber app logo displayed on a mobile telephone, as it is held up for a posed photograph in central London, Britain October 28, 2016. REUTERS/Toby Melville/Illustration

The California Department of Motor Vehicles on Wednesday revoked the registration of 16 cars in Uber’s self-driving fleet, which the regulator said lacked the proper permits.

Arizona, however, does not require any special permits for self-driving cars, according to the state Department of Transportation. Autonomous vehicles have the same registration requirements as any other car.

Uber’s self-driving program had been running in San Francisco for just a week, and all the while the company was embroiled in a dispute with the state DMV and attorney general. Both threatened legal action if Uber did not remove its self-driving cars from the road, which the company ultimately did on Wednesday.

On Thursday morning, Uber loaded its cars onto long-haul trucks belonging to Otto - a self-driving truck company Uber acquired in August.

“Our cars departed for Arizona this morning by truck,” an Uber spokeswoman said in a written statement. “We’ll be expanding our self-driving pilot there in the next few weeks.”

San Francisco had been selected as Uber’s second testing ground for its self-driving cars after Pittsburgh, but the company immediately faced a backlash from the DMV, which requires that any company testing autonomous vehicles on public roads receive a permit.

But Uber refused to apply for the permit, arguing that state regulations do not apply to its cars, which require constant monitoring and interference by a person in the vehicle.

California defines autonomous vehicles as having the capability to drive “without the active physical control or monitoring of a natural person.”

Amid the fray, Arizona Governor Doug Ducey invited Uber to bring its cars to his state.

“Arizona welcomes Uber self-driving cars with open arms and wide open roads,” Ducey said in a statement released Thursday. “While California puts the brakes on innovation and change with more bureaucracy and more regulation, Arizona is paving the way for new technology and new businesses.”

Alphabet Inc’s autonomous car division Waymo is also testing in Arizona.