A self-driving Ford Fusion hybrid car is test driven, Thursday, Aug. 18, 2016, in Pittsburgh. Uber said that passengers in Pittsburgh will be able to summon rides in self-driving cars with the touch of a smartphone button in the next several weeks. The high-tech ride-hailing company said that an unspecified number of autonomous Ford Fusions with human backup drivers will pick up passengers just like normal Uber vehicles. Riders will be able to opt in if they want a self-driving car, and rides will be free to those willing to do it, spokesman Matt Kallman said. (AP Photo/Jared Wickerham)

The immediate future of driverless cars…is driverless cars with drivers. And passengers.

Later this month, Uber will start ferrying customers around Pittsburgh in decked-out driverless Volvos, with chaperones in the front seat ready to take over at tricky spots, according to a report in Bloomberg Businessweek.

It would be the first time regular U.S. customers will be able to hail a relatively driverless ride, though other companies and cities are promising similar small-scale projects soon.

Uber is one of a rush of companies trying to get a jump on what some analysts say will be a multi-trillion-dollar market. Ditching expensive drivers and using cars that today sit idle the great majority of time will bring radical changes to transportation, proponents say.

Uber chief executive Travis Kalanick has described his driverless plans in existential terms. “He said to me, ‘Have you ever heard of the Manhattan Project?’ I said, ‘Yeah,’ ” Pittsburgh Mayor Bill Peduto said in an interview earlier this year. “He said, ‘In California, we call it the Pittsburgh Project.’ ”

The company hired dozens of key robotics engineers from Pittsburgh’s Carnegie Mellon University, which is seen as a cradle of autonomous driving research. It also acquired driverless truck startup Otto, Uber announced in a blog post Thursday.

Uber users in Pittsburgh will be chosen randomly when they use the company’s app, and the rides will be free, according to Bloomberg, which said a “handful” of Volvos have already been delivered and 100 are expected by year’s end. Volvo and Uber are aiming to develop a “fully autonomous” car by 2021, according to Bloomberg.

“Partnership is crucial to our self-driving strategy because Uber has no experience making cars,” Uber said in a blog post Thursday. “By combining Uber’s self-driving technology with Volvo’s state-of-the art vehicles and safety technology, we’ll get to the future faster than going it alone.”

Ford announced plans this week for a major push to make autonomous cars. Uber will also use Ford Fusions in the Pittsburgh pilot. The timeline for expanding to other cities remains unclear.

General Motors and Lyft also have plans to launch an on-demand, autonomous service, also with drivers in the front seat as a way of easing customers into the experience, according to GM.