Google's prototype self-driving cars were due to hit California roads by this summer, and now the company has announced they are ready and already cruising down the streets of Mountain View.

The cute vehicles, which were first announced last year without any driver controls, are a little different than the original builds, as they now include manual controls and require a driver to be available. They're therefore similar to Google's self-driving Lexus SUVs, which have been going around the company's campus for a while now, but the new ones have been approved for street-use.

"These prototype vehicles are designed from the ground up to be fully self-driving," Google explained via a Google+ post. "They’re ultimately designed to work without a steering wheel or pedals, but during this phase of our project we’ll have safety drivers aboard with a removable steering wheel, accelerator pedal, and brake pedal that allow them to take over driving if needed."

The prototypes use the same software that the Lexus vehicles use, which have self-driven over 1 million miles since their debut, but they can't go over 25 miles per hour. It'll be interesting to see how this testing phase goes. Google has said in the past that it wants to conduct several self-driving pilots over the next few years, so we can assume we're still in early-days territory here.

Check out Google's Self-driving car page to learn more about the project.

READ: This is Google's 'first real build' of a self-driving vehicle