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.

Daniel Filip, Tech Lead Manager for Google Maps, carries the Trekker, a 15-camera device, while mapping the Inca citadel of Machu Picchu for Google Street View in Cuzco, Peru, August 11, 2015. (Photo by Pilar Olivares/Reuters)

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)

The love padlocks, called cadenas d’amour, multiplied until there were thousands of love tokens on the bridge, each engraved with a message of love. (Photo by Charles Platiau/Reuters)

Triumph International's lingere set of bra and underwear come with a lock attached to the shorts and a key for the woman to give the key to her beloved on November 24, 2004 in Tokyo, Japan. (Photo by Koichi Kamoshida/Getty Images)

Locks hang on a fence along the Cliff Walk in Newport, Rhode Island July 14, 2015. They say the whole world loves a lover, but in Newport, Rhode Island, at least, not everyone is fond of the so-called “love locks” that sweethearts are leaving along the resort city's famed seaside Cliff Walk. Hundreds of the padlocks left behind by tourists as romantic tokens now cover sections of a chain-link fence along the route. Each is meant to represent the bond lovers shared during their visit. By custom, the key is thrown away. (Photo by Brian Snyder/Reuters)

Scientist Jiri Sindelar checks a ring of a Boreal owl chick outside the “Smart Nest Box”, which allows the study of birds by using mounted cameras, in a forest near the village of Mikulov, Czech Republic, June 18, 2016. (Photo by David W. Cerny/Reuters)