He watched as the Tesla tandem conducted a left turn at a street up ahead of him, disappeared around the block for half a mile, then drove by him again—once, then twice, then again and again. 

“That’s all they did—around the same block over and over and over, all day long,” Pfister says in an interview.

Since Pfister’s spotting of the vehicles a few weeks ago, a handful of white Teslas (and some black and gray Teslas too) have frequented the streets of Pfister’s small neighborhood, driving the same routes and taking the same turns repeatedly—typically with drivers in the front seat, though two residents in the neighborhood that Fortune interviewed say they have seen some driverless vehicles with someone in the passenger seat. Another resident saw Teslas without anyone in them at all on multiple occasions.

Tesla is testing the vehicles in the neighborhood as it gears up for a long-anticipated launch of its self-driving taxi service in Austin by the end of this month. The EV company, which has been working on autonomous technology for more than a decade now, has said it is finally ready to go up against robotaxi competitors like Alphabet, whose subsidiary Waymo has already offered 10 million paid rides and is operating in four cities and planning to launch soon in several more. Elon Musk has assured investors that Tesla’s robotaxi service, which will initially start small with 10 to 20 vehicles, will expand to several other cities before the end of the year. But it all will start in Austin—and specifically in this small neighborhood—as Tesla proves its concept and irons out any kinks.

When the sightings of Tesla’s robotaxis began a few weeks ago, they raised alarm among some of the people who lived in the neighborhood. A couple of residents took to the community messaging platform Nextdoor to query their neighbors as to why white Teslas—with drivers—were parking in front of their houses for long stretches of time. “It’s freaking me out,” one woman posted.

Anastasia Maren, 24, who moved into the neighborhood last month, said she has seen Teslas drive by or park in front of her duplex repeatedly since she moved in, particularly when she is going on walks.

“They stare you down as if you’re in their way, or you’re the one who shouldn’t be here,” Maren says of the drivers. She says that while she has sometimes seen the vehicles driving around with only someone in the passenger seat—she often sees a person in the driver’s seat controlling the vehicles. “Sometimes I can see the person actually turning the wheel,” she says.

A 37-year-old Austin resident, Robert Yeats, who lives in an apartment complex further north in the neighborhood than Maren and Pfister, says he sees white Teslas line up in front of his apartment, parked and with their hazard lights on, often in groups of about four. In some cases, the Teslas were parked in the middle of the road with their hazard lights on, forcing other drivers to go around them. According to one resident, the tests have occurred as late as 10 p.m. None of the residents Fortune spoke to said they had received any notice or information from Tesla about the testing in their neighborhood.

Austin residents are used to seeing self-driving vehicles around town. Waymo’s cars started mapping the city in 2023 with safety drivers on board, and has since begun offering passenger service around the city without safety drivers in the vehicles. Pfister told Fortune he has seen Waymos parked overnight in front of empty lots in the same neighborhood. A few years ago, Cruise had released robotaxis on the streets of Austin, back before parent company General Motors stopped all rides, and later shut down the ride-hail service, after a high-profile accident in San Francisco.

But the Tesla sightings add to the questions that many industry observers have about the viability of the company’s technology and approach to autonomous driving. While other autonomous vehicle companies have needed to digitally map roads and neighborhoods before launch, Tesla claims that its camera-only system doesn’t require high-definition mapping, radar, or lidar technology. According to the company, its approach to autonomous driving is less expensive and more adaptable than the competition: instead of mapping an area for months, Tesla cars can figure out the terrain wherever they are.  But if that’s the case, why are Teslas driving around the same streets of one neighborhood over and over—and why do many of the vehicles have someone driving them?

“I thought, well, maybe they’re just in the driver’s seat, so that if something goes wrong, they can grab the steering wheel. But they are actually driving the car,” Pfister says, noting that he has seen the drivers with their hands on the steering wheel. “They are actually driving the car, so it’s not driverless. I don’t really understand.”

Tesla did not respond to a request for comment.

Tesla has also conducted testing in at least two other locations in Texas. There was a scheduled testing with emergency vehicles in a separate isolated street in Austin, as Fortune earlier reported. Tesla also did testing at a training facility in Florence, Tex., with the Texas Department of Public Safety’s crash reconstruction team. During that event, state agencies set up scenarios for Tesla’s robotaxis to operate, so that the company could collect information about how to respond to various encounters with emergency personnel and equipment, such as crash scenes or flashing lights and sirens, according to a spokesperson for the Texas Department of Public Safety.

But it’s along a few blocks of the neighborhood in southeast Austin where Tesla has been conducting its regular, real-world testing in the weeks before launch. There’s a Tesla Supercharger station just across a busy street—the only station for about two miles—as well as a Tesla collision center less than two miles down the road. The neighborhood itself features quiet streets, though Teslas will have to cross a busy road to get to the charging station. There aren’t sidewalks on the residential streets, so residents walk their dogs or push strollers on the street itself—giving the cars an opportunity to operate with obstacles in a controlled environment. The three residents tell Fortune that the cars appear to operate at speeds no greater than 25 miles per hour.

Tesla is nearing the end of the June deadline that Musk set for launch—with just three weeks until the end of the month. A Bloomberg report had suggested the company was aiming for a June 12 launch. But as of Tuesday, June 10, several important pre-launch checklist items appeared to be outstanding. Tesla had provided drafts, but not finalized emergency responder guides, nor had it conducted emergency responder trainings to the Austin Transportation and Works Department of the Austin Fire Department as of Tuesday, the agencies told Fortune. As Fortune earlier reported, the EV maker told city employees those items would be furnished before the company launches service.