Last December, Uber clashed with California regulators when it tested its self-driving cars in San Francisco without permission from the California Department of Motor Vehicles. The company was quickly ordered to shut down its trials.
Uber’s executives called Mr. Ducey.
“We responded by saying we weren’t going to hassle them,” Mr. Ducey said of Uber. “I’d be remiss if I didn’t thank my partner in growing the Arizona economy, Jerry Brown,” the Democratic governor of California.
Days later, Uber loaded a fleet of driverless sport utility vehicles onto semi trucks headed for Tempe. The company now has several dozen driverless cars in a garage there that is the size of two football fields, with plans to add more cars.
“Governor Ducey’s prioritization of the sharing economy has made the Grand Canyon State an ideal environment for our self-driving pilot,” Uber said.
Under Mr. Ducey, driverless car experiments in Arizona have multiplied over the last year.
Uber’s self-driving Volvo SUVs now pick up customers around Tempe on a daily basis. Waymo has dispatched more than 100 Chrysler self-driving minivans to chauffeur select families and other residents as part of a closely guarded trial; the company plans to expand to 600 vehicles by the end of the year, with the majority in Chandler. And dozens of vehicles for GM, Ford, Intel, and Lyft are also covering thousands of miles a day on the flat and sun-drenched roads around Phoenix.
Some residents are ambivalent. Groups representing the blind are enthusiastic supporters of driverless cars, which could give their members more independence. Others like the idea of tech-related jobs coming to the state. But some are cautious.
“I’m on the fence,” said Jake Guadarrama, 22, a Phoenix area resident. “What if the battery died on the car and it goes out of control? And will it take way from the work force?”
Those questions are not just academic. Already, the incorporation of driverless cars into human-driven traffic has run into problems.
Around dusk on March 24, for example, Alexandra Cole, a Tempe resident, inched her 2008 Honda CRV into a busy suburban intersection in the city. With five seconds left on the pedestrian crossing signal and no cars coming toward her in the two closest lanes, she began a left turn.
She did not see Uber’s self-driving Volvo SUV darting through the yellow light in the furthest lane toward her. The cars collided. Uber’s vehicle flipped onto its side and crashed into two more cars waiting in traffic.
The crash — Arizona’s first with a driverless vehicle — was soon resolved. There were no injuries and police said Ms. Cole, and not Uber’s car, was to blame for failing to yield on a left turn.
But what happened after the accident revealed a system that was unprepared for computer-operated vehicles. Mr. Ducey, Tempe officials and state transportation regulators did not get briefed on the collision. The self-driving task force set up by the governor, which has met twice in two years, also did not review the incident.
Uber sent its wrecked vehicle to its Pittsburgh-based autonomous vehicle center, which the National Highway Transportation Safety Administration officials visited to investigate. N.H.T.S.A. said it could not comment because its investigation is still in progress. Ms. Cole and her insurance company declined to comment.
If the crash had turned into a criminal case, police would likely have asked for data from the self-driving cars. If the carmakers refused, they might have sought warrants for the data — a practice that put the Federal Bureau of Investigation and Apple into a fierce battle last year related to unlocking an iPhone used by a suspect in a mass shooting. Waymo and Uber said their policies are to comply with local laws wherever they operate.
Insurance would also have been a question, with debate over who takes responsibility in a driverless car crash — the company or the third-party software or parts makers or the passenger with a license — since there is no driver.
“The insurance companies need to figure out how they will insure this,” said Stephen Briggs, a spokesman for Arizona’s Department of Insurance. Arizona hasn’t changed its minimum insurance liability rules for self-driving car trials. “The government doesn’t have the resources to do this.”
Angel Carbajal, Tempe’s assistant chief of police, acknowledged there are many unknowns. “This is new, so there isn’t a lot of legislation yet that explains how to respond to motor vehicle collisions involving autonomous vehicles,” he said.
For Mr. Ducey, none of this is a problem. He said the crash was handled properly and that even if driverless technology is not fully ready, the state’s bet on autonomous vehicles will continue.
“These are cultural opportunities for Arizona to be seen as a place to live, work and play,” he said.