A self-driving pilot has got underway in San Francisco, as part of an agreement between Volvo and ride-sharing technology company Uber.

Using specially converted Volvo XC90s, Uber is expanding its ongoing self-driving pilot, marking the next phase in a working relationship with Volvo. The two companies signed an agreement in August 2016 to establish a jointly owned project to build base vehicles that can be used to develop fully autonomous driverless cars, which were initially tested in Pittsburgh, Pennsylvania.

The latest cars to be used in San Francisco have been built by Volvo and sold to Uber, after which Uber’s own self-driving hardware and software package has been added, most visibly in the roof-mounted control apparatus.

These cars will drive the streets of San Francisco autonomously, but as part of the pilot programme, they will have an Uber technician on board all times to supervise the car’s operation.

“The promise of self-driving ride sharing is becoming a reality,” said Mårten Levenstam, vice president product planning at Volvo Cars. “Volvo is proud to be at the forefront of the latest developments in the automotive world alongside our partners at Uber.”

The alliance with Uber forms one part of Volvo’s three-part plan to develop autonomous driving (AD) technologies.

In January 2017, Volvo will begin a project entitled Drive Me, which will be the world’s largest autonomous driving test, with up to 100 self-driving cars given to members of the public to be driven on real roads around Gothenburg, Sweden. Their experiences will be used to co-develop Volvo’s AD cars.

The second part is a joint venture with automotive safety technology company, Autoliv, to set up a new jointly owned company to design and manufacture separately branded AD and driver-assistance software technology packages for sale to third-party companies. The new company will have its headquarters in Gothenburg, opening early next year with an initial workforce taken from both companies of around 200, increasing to more than 600 in the future.

The third part is the ongoing relationship with Uber to build and co-develop base vehicles for AD cars. This deal reduces the car giants development costs, gives it a chance to develop cutting-edge technology and could ultimately 'boost sales significantly', says Volvo.

The base vehicles will be manufactured by Volvo and then purchased from Volvo by Uber. Volvo Cars and Uber are contributing a combined $300m to the project and both will use the same base vehicle for the next stage of their own autonomous car strategies.