LOS ANGELES — Google plans to build and launch onto city streets a small fleet of subcompact cars that can operate without a person at the wheel.
Actually, the cars wouldn’t even have a steering wheel. Or gas and brake pedals. The vehicles will use sensors and computing power, with no human needed.
Google hopes that by this time next year, 100 of the two-seaters will be on public roads, after extensive testing. The cars would not be for sale but would be provided to select operators for further tweaking. They have limitations, such as a top speed of 25 miles per hour.
Google’s plans, announced Wednesday, present a challenge to automakers that have been more cautious about introducing fully automated vehicles and to regulators, who are scrambling to accommodate self-driving cars on public roads. Others are working on the technology, too, but no company as large as Google Inc. has said it intends to put such cars in the hands of the public so soon.
Google has driven hundreds of thousands of miles on public roads and freeways in Lexus SUVs and Toyota Priuses outfitted with sensors and cameras. But with a human ‘‘safety driver’’ in the front seat, those vehicles were not truly self-driving.
Instead of standard controls, the prototypes will have buttons to begin and end a drive. Passengers will set a destination. The car will then make turns and react to other vehicles and pedestrians based on programs that predict what others might do and data from the sensors, including radar.
The route might be set by typing a destination into a map or speaking a command, said Chris Urmson, leader of Google’s self-driving-car team.
The car will be powered by electricity and could go about 100 miles before recharging. Its shape suggests a rounded-out Volkswagen Beetle — something that might move people around a corporate campus or a congested downtown — with headlights and sensors arrayed to resemble a friendly face.
Major automakers have steadily introduced technology that helps cars stay in lanes and avoid accidents. All those vehicles come with a steering wheel and pedals — and the expectation that a driver will jump in should trouble arise. Several companies have said they expect by 2020 to market vehicles that can drive themselves under certain conditions.
‘‘Nothing is going to change overnight, but [Google’s announcement] is another sign of the drastic shifts in automotive technology, business practices, and retailing we’re going to witness,’’ said Karl Brauer, a senior analyst at Kelley Blue Book.
A French company, Induct Technology, has produced a driverless shuttle, which in February drove people around a hospital campus in South Carolina. But in terms of a truly self-driving car from a major company, Google looks to be first.
The first 100 prototypes will be built in the Detroit area with help from companies that specialize in autos. Google would not discuss costs.
This summer, Google plans to test cars on closed courses, then later this year on public streets. They will have a wheel and pedals; under California law a driver must be able to take control. By summer 2015, though, California’s Department of Motor Vehicles must publish rules allowing the public to use true driverless cars.