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 rebel fighter carries his weapon as he moves through a hole in a wall in the old city of Aleppo near the frontline against forces loyal to Syria's President Bashar al-Assad December 28, 2014. (Photo by Jalal Al-Mamo/Reuters)

Vlada Nikolchenko of Ukraine performs with the ribbon during the 36th European Rhythmic Gymnastics Championships in Kyiv, Ukraine, Sunday, November 29, 2020. Athletes from 23 countries participate in the championship in Kyiv. (Photo by Efrem Lukatsky/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)

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)

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)

Activists from the animal rights group PETA wearing bikinis and crocodile masks assist each other outside a store of the French fashion label Hermes in Sydney on March 4, 2021, as they protest against their use of crocodile skins and the recent purchases by Hermes and LVMH of crocodile farms in Australia's Northern Territory. (Photo by David Gray/AFP Photo)