Gov. Jerry Brown rode to Google headquarters in a self-driving Toyota Prius before signing legislation Tuesday that will pave the way for driverless cars in California.The bill by Democratic Sen. Alex Padilla will establish safety and performance regulations to test and operate autonomous vehicles on state roads and highways.Autonomous cars can make roads safer, free commuters from the drudgery of driving, reduce congestion and provide transport to people who can't drive themselves, such as the blind, disabled, elderly and intoxicated.