California's 1st driverless bus debuts in San Ramon The first driverless bus in California received permission to operate.

The first driverless bus approved for use on public roads in California debuted on Tuesday, as local leaders lauded the potential of such vehicles to improve public-transit outcomes in and around the city of San Ramon.

"It's a momentous day for San Ramon and for Bishop Ranch," Mayor Bill Clarkson told ABC station KGO-TV in San Francisco.

Bishop Ranch, a 585-acre office park where approximately 30,000 work, proved fertile testing grounds for the shuttle, and commuters to the area may be among the first to benefit from further deployments. Contra Costa County may be using as many as 100 of the buses by 2020.

The EasyMile shuttle can accommodate a dozen people -- six sitting and sit standing. It was approved by the state's department of motor vehicles after the federal government signed off.

"This is one of the great transformations in public transportation," Alex Mehran, chief executive officer of Sunset Development, which oversees the property, told KGO-TV.

Commuters will be able to try the service beginning April 27, as testing continues. An attendant will join commuters on board, at least for the time being, to answer their questions and push a button in case of an emergency.