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.

March 11, 2008 Swiss car manufacturer Rinspeed made quite the splash at the Geneva Motor Show with its innovative sQuba, a fully functional submersible concept car that cost $1.5 million to build. (Photo by Rinspeed)

A group of policemen and passers-by survey the wreckage of a taxi in Stoke Newington, London. Its front wheel lies on the pavement next to a sign bearing the ironic instruction “All Cars Stop Here”. 14th February 1930. (Photo by Fox Photos). P.S. All pictures are presented in high resolution.

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)

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)

Two terrified occupants of a Volkswagen Polo found themselves in the wrong place at the wrong time as the giant animal stooped down to rub itself against the vehicle's roof and bonnet. The incredible scene was captured by field guide and lodge manager Armand Grobler, 21, at Pilanesburg National Park in South Africa. (Photo by Armand Grobler/Barcroft Media)

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)