FORTUNE — Google’s four-year experiment with self-driving cars has shown the technology’s great potential. People can just sit back and relax while computers ferry them around town.

Now Google wants to take the next step by designing and building a fleet of 100 driver-less cars – albeit without steering wheels, gas peddles, brakes and mirrors. Why install standard controls if no one is going to use them?

Google announced the plans late Tuesday, showing once again its big appetite for futuristic projects. The initiative also shows just how serious the company is about driver-less technology while also raising questions about whether it intends to become an auto manufacturer.

Until now, Google has used modified Toyota Priuses and Lexus SUVs in its tests on city streets and highways. They’ve traveled more than 700,000 miles on auto-pilot and navigated through most of the potential complex situations that drivers deal with on a daily basis.

Google GOOG has already built a prototype of the next generation vehicle that is rounded and compact like a Mercedes-Benz Smart car with a device on the roof that looks like a fast-spinning mini-radar. The car is big enough for only two passengers and features a minimalist dashboard with merely an on and off button, and a screen for a digital map.

Computers do the driving by relying on sensors to detect location and any obstructions in the road. Humans don’t need to do anything except get inside, fasten their seatbelts and indicate their destination. A video of the car in action is here.

“It was inspiring to start with a blank sheet of paper and ask, ‘What should be different about this kind of vehicle?’” Chris Urmson, director of Google’s self-driving car project, said in a blog post.

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Google stressed that safety was a key consideration in its own design. Early prototypes will have their speed capped at 25 mph, making them too slow to operate on a highway. To keep pedestrians from being injured in any collisions, the company has designed the cars with foam in the front and a flexible windshield.

Earlier this month, California approved the use of driver-less cars on public roads. The company plans to start testing early versions of the vehicle, which will be equipped with manual controls, just in case. If all goes well, it hopes to expand the testing program in the next few years in California. Eventually, Google said it may bring in partners to help develop its driver-less cars. But the company did not address the key question: Does it plan to sell driver-less cars to the public or just commercialize the underlying technology.

“The project is about changing the world for people who are not well-served by transportation today,” Sergey Brin, Google’s co-founder, said Tuesday at the Code Conference in Rancho Palos Verdes, California, according to an article by Re/code, the technology news site that hosted the event. “There’s not great public transportation in many public places in the United States.”