PITTSBURGH — Very soon, residents of this hilly city will become the first Americans to test out Uber's self-driving car service. It's a historic moment not just for the ride-hailing company, but for robotic cars in general: For many people, this will be when the technology becomes a reality, one they can touch and experience for themselves rather than read about in the media.

Uber has been conducting its driverless car tests on open roads since May. People around here say they've often seen the company's prototypes driving around the city, their rooftops laden down with sensors and communications equipment. But the project has otherwise been shrouded in secrecy, even from the drivers who sometimes ferry Uber employees to work in the Strip District.

Hence, what Pittsburgh locals think about Uber's driverless cars has mostly been shaped by what they've observed with their own eyes. And their reactions run the gamut — from hope that the new technology will contribute to their city's story of renewal, to questions about the cars' performance on Pittsburgh's complicated road network, to concerns about how the vehicles will affect the local economy.

Interviews with city residents reveal that some are reluctant to trust a technology that Uber has kept so close to the vest.

"It's scary, being driven by a robot," said Ada Gana. "A person who's driving knows what he's doing or where he's going. That gives me confidence."

Uber staffs each of its driverless cars with two full-time employees — one person to grasp the wheel and another to keep an eye on the computer software. That won't change when the company debuts its driverless service. But not all those who live here are aware of that. Some believed the cars would be completely empty, which suggests Uber has a lot of education to do.

That's particularly the case for seniors, said Eva Tsuquiashi-Daddesio, who's 67 years old.

"If Uber or other companies want to be successful with the older population, they need to do a lot of demonstrations. Talk is not going to do anything," she said. "[Seniors] have to see other people like them — like us, I suppose — using it, and they will have to see that it is safe."

Even some relatively younger people say they would be hesitant to try a self-driving Uber, though many predict that university students here will be among the most eager adopters.

For Uber drivers, though, it's no surprise that employment is the bigger concern.

Michelle Garrison has four children — including two teenagers — and treats driving for Uber as a full-time job. She wakes up at 5:15 a.m., Monday through Friday, and doesn't stop picking up passengers until 6 in the evening.

"I personally don't care for it," she said of the self-driving car testing. "I think it's going to take jobs away from some of us. It's going to take away from the actual drivers that are out here that are putting in the time and the hours."

Uber's chief executive, Travis Kalanick, has said he doesn't expect the number of human drivers to decline anytime soon, and that self-driving technology will create new jobs, such as for fleet maintenance.

But that's not enough to alleviate some Uber drivers' worries. A few have signed on with a group called Cabbie Central, a Pittsburgh-based organization that represents nearly 250 people who drive for taxi and, increasingly, ride-hailing services. Although they compete intensely for the same customers, drivers for both taxis and Uber are discovering they have much in common in the face of Uber’s automation experiments, said Jim Jacobs, the general manager of Cabbie Central and a taxi driver who has been in the business for 11 years.

Uber’s aggressive timetable in debuting an autonomous service has forced many of its drivers to grapple with an uncomfortable reality much sooner than expected, said Jacobs: This is what planned obsolescence really looks like.

Yet not all are concerned. Many view their gig with Uber as a part-time or temporary job. "It hasn't affected me yet, and I'm not career-sold on doing this forever," said Jason Renton, a driver who lives a half-hour from downtown Pittsburgh. "So no, it doesn't really bother me."

Renton and other drivers say that the majority of their customers — they estimate from 70 percent to 95 percent — are skeptical of the technology.

There are still a lot of questions. Some residents worry about the ability of a self-driving car to successfully navigate to a rider's location, or to avoid sudden road closures. Pittsburgh is said to be a tough — as in "good" — test case for self-driving vehicles, because the city has hills, bridges and older streets. On Sept. 2, a construction accident on the Liberty Bridge caused a fire that was so hot that it melted part of the bridge's support structure.

The bridge has been closed for weeks, causing commuter headaches. But Uber's navigation system didn't appear to know about the bridge closure, said Shiquita Crumbley, a Pittsburgh native who started driving for Uber a few months ago.

"GPS's are not always correct," she said. "It might take you to this bridge, not necessarily knowing, hey, this bridge is not open, you can't go on it. So, just making sure it's the most updated version. That's going to be the biggest, biggest thing for everyone's safety." For the foreseeable future, navigation may not be a big issue for the self-driving cars, as the Uber employee behind the wheel can always take over.

Local transportation activists say they support Uber's effort. "People are bad at driving," said Scott Bricker, executive director of the bicycling advocacy group Bike Pittsburgh. "Recently, a Pittsburgh bicyclist posted video of a self-driving Uber test car giving him space and passing at a slower speed in contrast to a car driven by a person. … If you ask me, taking the human factor out of driving can't happen fast enough."

Other local residents say the program helps put Pittsburgh on the map. In recent years, an influx of new money has brought tremendous growth for the former industrial powerhouse, reversing decades of decline.

"A lot of people have regional pride in the universities, big companies like Uber and Google being here," said Hassan Khan, a doctoral student at Carnegie Mellon University. Uber's self-driving program, he said, "fits that narrative of Pittsburgh being a resurgent city through tech, through medicine."