Uber's self-driving vehicles are coming home... to the ride-hailing service's hometown of San Francisco, that is.

Uber, which already operates a fleet of self-driving vehicles in Pittsburgh, said on Wednesday that it is unleashing a fleet of Volvo XC90 luxury SUVs onto the streets of San Francisco to service customers that request an UberX.

This is a step up from the Ford Fusion vehicles the company deployed in Pittsburgh in September as the Volvos feature more tightly integrated autonomous driving technology, TechCrunch reports.

That said, Uber's latest vehicles aren't operating completely driverless at this point. Indeed, there will be a safety driver in the driver's seat as well as an Uber engineer in the front passenger seat to monitor progress, collect data and so forth.

It's also worth mentioning that there's no guarantee that you'll be matched up with one of the new autonomous rides. It's unclear how many self-driving vehicles Uber is deploying although I suspect it's not very many.

Uber in announcing the rollout addressed the issue of whether or not it needs a testing permit to launch the fleet in San Francisco.

After studying the matter carefully, the company came to the conclusion that it does not need a permit. Uber says the permit rules apply to vehicles that can drive without someone controlling or monitoring them. Its Volvo SUVs still require human operators on hand to monitor and take over control should something go wrong.