Ride-sharing service Uber will offer the option of hailing a self-driving car in the United States — the first time the technology has been offered to the general public.

The company announced on Thursday, customers will within weeks the ability to opt into a test program and summon a self-driving Ford Fusion.

But since the technology has not been perfected, the cars will come with human backup drivers to handle any unexpected situations.

Although other companies including Google are testing self-driving cars on public roads, none offers rides to regular people. As an enticement, the self-drive rides will be free, the company said.

Uber, which has a self-driving research lab in Pittsburgh, has no immediate plans to deploy self-driving cars in other cities.

But in an interview with The Associated Press, CEO Travis Kalanick said development of the vehicles is paramount for the San Francisco company, which has grown exponentially after starting seven years ago.

“We’ve got to be laser-focused on getting this to market, because it’s not a side project for us,” he said.

“This is everything. This is all the marbles for Uber.”

Without drivers, the cost of hailing a ride will be cheaper than owning a car, changing the way we all get around, Kalanick has said.

Uber’s net revenue was forecast to treble to more than $A1.5 billion in the 2016 financial year, according to leaked documents published early this year.

By using human backup drivers, Uber is basically testing the technology and taking people along for the ride, said Bryant Walker Smith, a University of South Carolina professor who studies self-driving technology.

“Part of this is marketing in the sense that they’re going to be doing continued research and development of these systems,” he said.

Over the long term, Uber and rivals such as Lyft could cut the cost of paying drivers if they can gradually incorporate self-driving cars into their fleets.

– with agencies.