Google has built its first self-driving car prototypes and hopes to test hundreds more models this summer. If all goes well, the company is planning a pilot program in California over the next few years.

Toyota Motor unveils a concept car the “PM”, is on display at a press preview for the Tokyo Motor Show in Makuhari, east of Tokyo October 23, 2003. PM is a single seater personal vehicle whose cabin posture changes from upright to reclined as speed increases. (Photo by Koichi Kamoshida/Getty Images)

A Toyota i-Road electric vehicle drives in a underground parking lot in Tokyo April 9, 2015. Tokyoites will get a chance to zip around town on Toyota Motor Corp's three-wheeled electric car-cum-motorbike from Friday, in a trial aimed at crafting a global business model to reduce gridlock and pollution. (Photo by Thomas Peter/Reuters)

Mohamed Badr al-Din (R) stands in front of his vintage cars along a street where he keeps them, in the al-Shaar neighborhood of Aleppo January 31, 2015. The 66-year-old collector nicknamed Abu Omar inherited the hobby from his father and has a large collection of vintage cars, some of which he says belonged to former Syrian officials and were used in several movies and shows. Before the unrest, Abu Omar planned to open a museum to display his cars, which are guarded from pedestrians by a turkey that he owns. He hopes that the turmoil in the country will end so that he can pursue his hobby and repair his cars, which are heavily damaged from shelling. (Photo by Abdalrhman Ismail/Reuters)

A worker makes auto parts on a machine inside a workshop in Faridabad, India, December 24, 2015. Car makers such as Maruti Suzuki India and Hyundai Motor see huge growth in India, set to become the world's third-largest auto market by 2020 as millions buy their first new car. Price tags can be as low as $3,000 for a new Tata Motors Nano mini-car. India is also becoming a low-cost export hub for global car makers such as General Motors and Ford Motor. As the sector expands, some of the work is sub-contracted out to small factories operating on paper-thin margins, where poor contract workers often have little or no access to safety equipment or health benefits. (Photo by Adnan Abidi/Reuters)

An Ambassador car, licensed as taxi rolls past other vehicles through a busy road in Kolkata, india, Monday, May 26, 2014. India's oldest car factory has abruptly suspended production of the hulking Ambassador sedan that has a nearly seven-decade history as the car of the Indian elite. (Photo by Bikas Das/AP Photo)

Medics carry an injured at the explosion site in the busy center of Turkish capital, Ankara, Turkey, Sunday, March 13, 2016. The explosion is believed to have been caused by a car bomb that went off close to bus stops. News reports say the large explosion in the capital has caused several deaths and many casualties. (Photo by AP Photo)

German carmaker Daimler's new Smart Fortwo car is seen on display during its world premiere in Berlin July 16, 2014. Daimler is betting that cooperation with Renault and the launch of models to tap growing demand for city cars may pave the way for its diminutive Smart brand to become profitable. Smart will add a new four-seater model to its lineup this year and upgrade the two-passenger Fortwo vehicle, raising hopes by the German group of boosting the brand's flagging sales. (Photo by Thomas Peter/Reuters)