"Nothing is going to change overnight, but (Google's announcement) is another sign of the drastic shifts in automotive technology, business practices and retailing we're going to witness," said Karl Brauer, a senior analyst at Kelley Blue Book's KBB.com.
A French company, Induct Technology, has produced a driverless shuttle, which in February drove people around a hospital campus in South Carolina. But in terms of a truly self-driving car from a major company, Google looks to be first.
The tech titan began developing the prototype more than a year ago after it loaned some employees its retrofitted Lexuses and saw that some "would basically trust the technology more than it was ready to be trusted," Urmson said. Making a car that drives itself seemed more practical than somehow ensuring that people zoning out behind the wheel could take over at a moment's notice.
The first 100 prototypes will be built in the Detroit area with the help of firms that specialize in autos, Google said. It would not identify those firms or discuss the cost of each prototype.
This summer, Google plans to send test prototypes on closed courses, then later this year on public streets. Those test cars will have a wheel and pedals because under California law a test driver must be able to take immediate control.
By summer 2015, however, California's Department of Motor Vehicles must publish regulations allowing the public to use truly driverless cars. Big questions the DMV is wrestling with include who is liable if a driverless car crashes and how the state can be confident that an automated car drives at least as safely as a person.
That change in the law would allow the 100 prototypes that would be intended for a public "pilot project"— details to be determined — to not have a steering wheel or pedals.
Though next year is the goal for the pilot project, public access "won't happen until we're confident in the safety," Urmson said.
Auto Writer Tom Krisher contributed to this report from Detroit.
Contact Justin Pritchard at https://twitter.com/lalanewsman .