Uber self-driving cars hit San Francisco streets, but good luck getting one

Catch a ride in a self-driving Uber.
Source: Uber

Uber said Wednesday that self-driving cars can now be summoned in San Francisco, where the company is headquartered. But good luck getting one, at least for now.

The cars are out there ... somewhere, but the system isn't flooded with them. For now, less than 10 self-driving vehicles are on San Francisco streets, Uber told CNBC. Uber has 43,000 drivers in the San Francisco Bay Area.

A CNBC reporter tried 15 times to summon a self-driving Uber on Wednesday morning and did not get matched with a self-driving vehicle.

San Francisco residents often get to try new tech-powered services before much of the world, since many Silicon Valley start-ups launch tests in the city. Each self-driving car has a vehicle operator — the artificially intelligent robot cars still need human supervision to be safe — for now.

Competition within the autonomous car space is growing — Google announced on Tuesday the spinoff of its self-driving car project into an independent company. Housed under the Alphabet umbrella, the new unit is called Waymo which stands for "new way forward in mobility," according to a company blog post.