If ever you're in San Francisco and called for an Uber, a Volvo XC90 might just roll up in front of your house by itself. That's because Uber and the Swedish automaker recently announced expanding their self-driving trials to San Francisco, California using the specially designed self-driving Volvo XC90 premium SUVs.

Back in August 2016, the two companies Uber and Volvo Cars had made an agreement to create base vehicles to be used for developing fully autonomous self-driving vehicles, which were first tested in Pittsburg, Pennsylvania.

Uber, Volvo Cars expand self-driving pilot testing to San Francisco

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

To ensure safety for everyone, the self-driving vehicles that will hit the San Francisco streets will be accompanied by an Uber technician at all times supervising the car's operations.

The partnership between the two companies is just one part of Volvo Car's three part plan to explore autonomous driving (AD) technologies. By 2017, the automaker will start its project called Drive Me, which will provide of up to 100 cars to be tested on Gothenburg roads.

Uber, Volvo Cars expand self-driving pilot testing to San Francisco

The second part is its alliance with Autoliv that aims to establish a new jointly-owned company, which will design and manufacture separately-branded AD as well as driver assistance software technology packages for sale to third party OEMs.

Lastly is the company's ongoing relationship with Uber to create and co-develop base vehicles for fully autonomous driverless cars.