CHANDLER, Ariz. — The assailant slipped out of a park around noon one day in October, zeroing in on his target, which was idling at a nearby intersection — a self-driving van operated by Waymo, the driverless-car company spun out of Google.
He carried out his attack with an unidentified sharp object, swiftly slashing one of the tires. The suspect, identified as a white man in his 20s, then melted into the neighborhood on foot.
The slashing was one of nearly two dozen attacks on driverless vehicles over the past two years in Chandler, a city near Phoenix where Waymo started testing its vans in 2017. In ways large and small, the city has had an early look at public misgivings over the rise of artificial intelligence, with city officials hearing complaints about everything from safety to possible job losses.
Some people have pelted Waymo vans with rocks, according to police reports. Others have repeatedly tried to run the vehicles off the road. One woman screamed at one of the vans, telling it to get out of her suburban neighborhood. A man pulled up alongside a Waymo vehicle and threatened the employee riding inside with a piece of PVC pipe.
In one of the more harrowing episodes, a man waved a .22-caliber revolver at a Waymo vehicle and the emergency backup driver at the wheel. He told the police that he “despises” driverless cars, referencing the killing of a female pedestrian in March in nearby Tempe by a self-driving Uber car.
“There are other places they can test,” said Erik O’Polka, 37, who was issued a warning by the police in November after multiple reports that his Jeep Wrangler had tried to run Waymo vans off the road — in one case, driving head-on toward one of the self-driving vehicles until it was forced to come to an abrupt stop.
His wife, Elizabeth, 35, admitted in an interview that her husband “finds it entertaining to brake hard” in front of the self-driving vans, and that she herself “may have forced them to pull over” so she could yell at them to get out of their neighborhood. The trouble started, the couple said, when their 10-year-old son was nearly hit by one of the vehicles while he was playing in a nearby cul-de-sac.
“They said they need real-world examples, but I don’t want to be their real-world mistake,” said Mr. O’Polka, who runs his own company providing information technology to small businesses.
“They didn’t ask us if we wanted to be part of their beta test,” added his wife, who helps run the business.
At least 21 such attacks have been leveled at Waymo vans in Chandler, as first reported by The Arizona Republic. Some analysts say they expect more such behavior as the nation moves into a broader discussion about the potential for driverless cars to unleash colossal changes in American society. The debate touches on fears ranging from eliminating jobs for drivers to ceding control over mobility to autonomous vehicles.
“People are lashing out justifiably," said Douglas Rushkoff, a media theorist at City University of New York and author of the book “Throwing Rocks at the Google Bus.” He likened driverless cars to robotic incarnations of scabs — workers who refuse to join strikes or who take the place of those on strike.
“There's a growing sense that the giant corporations honing driverless technologies do not have our best interests at heart,” Mr. Rushkoff said. “Just think about the humans inside these vehicles, who are essentially training the artificial intelligence that will replace them.”
The emergency drivers in the Waymo vans that were attacked in various cases told the Chandler police that the company preferred not to pursue prosecution of the assailants.
In some of their reports, police officers also said Waymo was often unwilling to provide video of the attacks. In one case, a Waymo employee told the police they would need a warrant to obtain video recorded by the company’s vehicles.
Officer William Johnson of the Chandler Police Department described in a June report how the driver of a Chrysler PT Cruiser wove between lanes of traffic while taunting a Waymo van.
A manager at Waymo showed video images of the incident to Officer Johnson but did not allow the police to keep them for a more thorough investigation. According to Officer Johnson’s report, the manager said that the company did not want to pursue the matter, emphasizing that Waymo was worried about disruptions of its testing in Chandler.
The report said Waymo was concerned about the effect the attacks were having on its emergency drivers, who are intended to remain in monitoring mode. “The behavior is causing the drivers to resume manual mode over the automated mode because of concerns about what the driver of the other vehicle may do,” Officer Johnson wrote.
In a statement, a Waymo spokeswoman said the attacks involved only a small fraction of the more than 25,000 miles that the company’s vans log every day in Arizona.
“Safety is the core of everything we do, which means that keeping our drivers, our riders, and the public safe is our top priority,” said Alexis Georgeson, the Waymo spokeswoman. “Over the past two years, we've found Arizonans to be welcoming and excited by the potential of this technology to make our roads safer.”
Ms. Georgeson said the company took the safety of its emergency drivers seriously and disputed claims that Waymo was trying to avoid bad publicity by opting against pursuing criminal charges.
“We report incidents we deem to pose a danger and we have provided photos and videos to local law enforcement when reporting these acts of vandalism or assault,” Ms. Georgeson said. “We support our drivers and engage in cases where an act of vandalism has been perpetrated against us.”
The authorities in Chandler and elsewhere in Arizona remain gladly open to Waymo and other driverless-car companies. Rob Antoniak, the chief operating officer of Valley Metro, which helps oversee the Phoenix metropolitan area’s transit system, said on Twitter that Arizona was still welcoming autonomous cars with “open arms” despite the attacks on Waymo vans.
“Don't let individual criminals throwing rocks or slashing tires derail efforts to drive the future of transportation,” Mr. Antoniak said.
But the official welcome mat has failed to persuade the naysayers.
One of them, Charles Pinkham, 37, was standing in the street in front of a Waymo vehicle in Chandler one evening in August when he was approached by the police.
“Pinkham was heavily intoxicated, and his demeanor varied from calm to belligerent and agitated during my contact with him,” Officer Richard Rimbach wrote in his report. “He stated he was sick and tired of the Waymo vehicles driving in his neighborhood, and apparently thought the best idea to resolve this was to stand in front of these vehicles.”
It worked, apparently. The Waymo employee inside the van, Candice Dunson, opted against filing charges and told the police that the company preferred to stop routing vehicles to the area.
Mr. Pinkham got a warning. The van moved on.