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)

The Flying Bull's P-38 Lockheed Lightning N25Y / 13 – Red Bull – Flying Legends Airshow 2012 Duxford (Photo by Rob Lovesey)

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)

A man carrying a woman wades through a flooded road following heavy rainfall in Zhengzhou, Henan province, July 21, 2021. At least 25 people have died in China's flood-stricken central province of Henan, a dozen of them in a subway line in its capital that was drenched by what weather officials called the heaviest rains for 1,000 years. (Photo by China Daily via Reuters)

Minoru Suzuki and Sanshiro Takagi, wrestlers from Japanese professional wrestling promotion DDT Pro-Wrestling, fight inside Tokaido Shinkansen bullet train from Tokyo to Nagoya during a wrestling show in Japan on September 18, 2023, in this handout photo released by JR Tokai (The Central Japan Railway Company). (Photo by JR Tokai/Handout via Reuters)

Portugal's Cristiano Ronaldo poses for a photo with Giuliana, a fan from Brazil, as he arrives with the Portuguese team at Lisbon airport to depart for the World Cup in Qatar, Friday, November 18, 2022. (Photo by Armando Franca/AP Photo)

Medical workers wearing protective gear to protect against coronavirus infection, carry a patient at infectious diseases hospital where patients with coronavirus are treated in St.Petersburg, Russia, Wednesday, June 3, 2020. (Photo by Dmitri Lovetsky/AP Photo)