Heads up! Uber's autonomous cars have arrived, and they appear to taking test runs all over San Francisco. I spotted one near Alamo Square Friday, and SFist's Eve got video this morning, showed above, of one crawling through traffic on Folsom near Fourth Street.

The logo on the side of the car was for Uber ATC (Advanced Technologies Center), and it looks like they're hiring. The cars themselves, developed in conjunction with a lab at Carnegie Mellon University in Pittsburgh, are kind of scary looking front on, as shown below.

Uber is of course in a race with Google to get these self-driving vehicles to market, and we know that Google already has a partnership with Ford to produce the things — and Ford is promising we'll be seeing self-driving taxis by 2021.

Critics, though are worried about the implications of self-driving vehicles filling a city's streets, not to mention they're worried about the nascent technology not being completely safe or well tested yet — ahem, Tesla.

Update: Uber tells the Chronicle that the vehicle was not driving itself, but a couple of these self-driving cars have been out on the streets conducting mapping work in SF — not, say, testing the self-driving capabilities as you'd think they're in a rush to do. Believe what you will.

Previously: Will Self-Driving Cars Ruin San Francisco?