If you're in San Francisco looking for a ride, you might be among the first to be picked up by an autonomous vehicle.

Uber is rolling out self-driving cars in the city Starting Wednesday, making it the second location in the company's autonomous initiative. Pittsburgh, home to the company's Advanced Technology Center, debuted the pilot program back in September.

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The self-driving vehicles, all Volvo XC90s courtesy of the Uber/Volvo partnership, will be matched with riders who request an uberX. Instead of displaying a driver's profile, the app will notify users the car on the way is a "Self-Driving Uber," with the option to cancel the trip and re-request a standard ride.

The vehicles are as autonomous as possible — but they aren't unmanned. Like Pittsburgh's cars, San Francisco's self-driving Ubers all have safety drivers in the front seat ready to take over control.

This human/machine combo fits Uber's current outlook on autonomous vehicles. When the company announced the program in Pittsburgh, the head of Uber's Advanced Technology Group Anthony Levandowski wrote "we believe ridesharing will be a mix — with services provided by both drivers and Self-Driving Ubers."

Uber looks to improve its self-driving tech by logging miles on the unique streets of San Francisco, which come "with its own nuances including more bikes on the road, high traffic density and narrow lanes," according to the blog post announcement.

But even with the safety drivers in place, the state of California isn't so sure about Uber filling the streets with its self-driving cars. The California DMV's regulations for testing autonomous vehicles require companies to register for the Autonomous Vehicle Tester Program to be granted a permit.

Image: uber/screengrab

Uber hasn't done that. When the vehicles hit the San Francisco roads, they'll be driving through a legal grey area.

When reached for comment, the California DMV gave Mashable the following statement on Uber's pilot program:

The California DMV encourages the responsible exploration of self-driving cars. We have a permitting process in place to ensure public safety as this technology is being tested. Twenty manufacturers have already obtained permits to test hundreds of cars on California roads. Uber shall do the same.

In response, Uber reps had no comment. They did, however, point Mashable to the last few paragraphs of the blog post announcement:

Finally, we understand that there is a debate over whether or not we need a testing permit to launch self-driving Ubers in San Francisco. We have looked at this issue carefully and we don’t believe we do. Before you think, “there they go again” let us take a moment to explain:

First, we are not planning to operate any differently than in Pittsburgh, where our pilot has been running successfully for several months. Second, the rules apply to cars that can drive without someone controlling or monitoring them. For us, it’s still early days and our cars are not yet ready to drive without a person monitoring them.

But there is a more fundamental point—how and when companies should be able to engineer and operate self-driving technology. We have seen different approaches to this question. Most states see the potential benefits, especially when it comes to road safety. And several cities and states have recognized that complex rules and requirements could have the unintended consequence of slowing innovation. Pittsburgh, Arizona, Nevada and Florida in particular have been leaders in this way, and by doing so have made clear that they are pro technology. Our hope is that California, our home state and a leader in much of the world’s dynamism, will take a similar view.

Whether or not the permitting disagreement becomes a real issue, Uber's cars will be on the streets in San Francisco starting Wednesday. With others like Google making their own moves in the self-driving, ride-sharing space, Uber needs to hit the road as soon as possible.