Several folks started noticing self-driving Uber cars in downtown San Francisco yesterday, fueling speculation the ridesharing company could soon be deploying autonomous vehicles for commercial use right where it all started in the Bay Area.

Mattermark editor in chief Alex Wilhelm snapped a picture of a white Ford Fusion stopped at the intersection of Montgomery and Pacific.

And, as first reported by Business Insider, Mercury Public Affairs senior vice president Drew Olanoff caught a black self-driving car making a left turn on Market Street near the Embarcadero at 6:45 a.m.

Other startup workers have been mentioning the sightings in the downtown area on social media as well, igniting suspicions this isn’t a one-off test.

These self-driving cars seen in downtown SF seem to be the same as those used in Uber’s self-driving pilot program in Pittsburgh. Uber recently deployed a fleet of 14 Ford Fusions equipped with radar, cameras and other sensing equipment developed by researchers from Carnegie Mellon University’s robotics center.

Pittsburgh Uber users are now able to opt in to hailing one of these 14 autonomous vehicles in town. But an Uber spokesperson tells TechCrunch that’s not the case with the self-driving cars spotting in SF.

“A handful of cars equipped with advanced driver safety and self-driving technology are now being tested in the Bay Area. These are for internal research use only. They will have a test driver upfront and will not be part of our ridesharing service. Testing in different environments is critical to the future success of this technology, which will help dramatically improve road safety,” Uber said.

So how long until riders here can choose to try out one of Uber’s self-driving cars? Uber said it didn’t have a timeline but did add it would keep us posted. We’ll be sure to let you know as soon as we hear more.