FILE - In this Sept. 25, 2012 file photo, Google co-founder Sergey Brin gestures after riding in a driverless car with California Gov. Edmund G Brown Jr., left, and state Senator Alex Padilla, second from left, to a bill signing for driverless cars at Google headquarters in Mountain View, Calif. The California Department of Motor Vehicles on Tuesday, March 11, 2014, held a public hearing to solicit ideas on how to integrate driverless cars, sometimes called "autonomous vehicles," onto public roads. (AP Photo/Eric Risberg, File)