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.

A Puffing Billy steam train hauled by locomotive 14A crosses the Monbulk Creek trestle after leaving Belgrave station near Melbourne, October 20, 2014. While the discovery of steam power 200 years ago powered the Industrial Revolution, the world long ago shunted most steam trains onto the sidings of history. (Photo by Jason Reed/Reuters)

A cloud of black smoke billows out the exhaust pipe of John Robertson's diesel dragster as he runs down the track during the 2015 NHRA Kansas Nationals, Friday, May 22, 2015, at Heartland Park in Topeka, Kan. (Photo by Chris Neal/The Topeka Capital-Journal via AP Photo)

China's Qinwen Zheng celebrates with fans after winning their second round match against Britain's Katie Boulter at the Australian Open in Melbourne on January 18, 2024. (Photo by Edgar Su/Reuters)

O Santa Claus of Australia competes in the mens 80–84 years 100 metres heats during day two of the 2009 Sydney World Masters Games at Sydney Olympic Park on October 11, 2009 in Sydney, Australia. (Photo by Mark Nolan/Getty Images)

A woman poses next to a giant mining truck at the entrance of the Dakar Rally camp in Calama, Chile. The truck operates in copper mines near the city. (Photo by Victor R. Caivano/Associated Press)

A rider rears up on his horse while surrounded by a cheering crowd during the traditional Fiesta of San Joan (Saint John) in downtown Ciutadella, on the Spanish Balearic Island of Menorca, June 23, 2014. The riders of the horses are representatives of ancient Ciutadella society – nobility, clergy, craftsmen and farmers. (Photo by Enrique Calvo/Reuters)

The Porsche 919 Hybrid No17 of the Porsche Team driven by Timo Bernhard of Germany is seen in action during the 83rd 24-hour Le Mans endurance race, in Le Mans, western France, Saturday, June 13, 2015. (AP Photo/David Vincent)