"That stop sign demarks the difference between private property and a public road," said Contra Costa Transportation Authority executive director Randy Iwasaki, seated in the front of the bus as it smoothly came to a stop.
The bus patiently waited for passing cars as it flashed its LED turn signal. Then, with the polite ding of a bell -- a real, analog bell -- it pulled out into traffic.
"Now we're on a public street," Iwasaki said. "You need a license or permission to operate from the California Department of Motor Vehicles."
At long last, the little bus, called an EasyMile shuttle, has that permission -- and a license plate to show for it -- even though it doesn't have a driver, or even a place for a driver to sit.
With a polite "ding" and the whisper of an electric motor, history was made at this stop sign today, as the first fully-autonomous shuttle bus drove onto a public street in California. It has no steering wheel or pedals, and carries 12 people -- plus a load of hopes and dreams. pic.twitter.com/iQyFtLZyzu— Jonathan Bloom (@BloomTV) March 6, 2018
"This is the first driverless shuttle in California that DMV has granted this permission to, so it's a really big deal," said DMV spokesperson Jessica Gonzalez.
Indeed, it's a big deal for local leaders, who held a press conference in celebration.
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"It's a momentous day for San Ramon and for Bishop Ranch," said San Ramon mayor Bill Clarkson.
Bishop Ranch is the sprawling 585-acre office park where some 30,000 people go to work every day, and where the shuttle's done laps in the wide-open parking lots for the past year. It took a break to be grand marshal of Concord's Independence Day parade, but had to ride on a tow truck while it waited for the state's green light.
"But what they had to do even before that was get permission from the Federal government, because the shuttle doesn't have a steering wheel or pedals," Gonzalez said.
She added that other autonomous vehicles being tested in California still require controls for a human driver, to comply with Federal law. But with its one-time exception, the EasyMile shuttle has more room for passengers.
"It seats comfortably six people, and you can stand six more in the middle here," Iwasaki said, gesturing to flat floor where he said a wheelchair could also safely park after coming up the shuttle's automatic ramp.
Bishop Ranch has proven an ideal test site for the EasyMile shuttle, but the people who work there may also be its ideal riders. To get there from the nearest BART stations, many workers board large buses that snake their way through the office park, making over a dozen stops.
"Today, our BART shuttles come into Bishop Ranch, and they have to spend about 15 minutes getting through the ranch," said Alex Mehran, CEO of Sunset Development, which oversees the property.
Mehran believes that by offering many individual routes that stop only once -- fanning out like the spokes of a wheel, instead of traveling around the rim -- taking public transit will become faster, and more commuters will opt to leave their cars at home. He's prepared to roll out dozens of EasyMile shuttles if there's demand.
But Contra Costa County has an even grander goal: nearly a hundred of the little autonomous buses by 2020. Officials see it as a solution to one of the biggest problems they identified in a study of the county's transit needs.
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"One of the problems that kept coming up was a first and last mile solution," Iwasaki said. "We can't get to the BART station, there's no parking."
So each morning, after dropping off workers at Bishop Ranch, county transit planners want the driverless shuttles to head into neighborhoods, where they'll pick up city-bound commuters headed to BART.
"This is one of the great transformations in public transportation," Mehran said.
Bishop Ranch will begin offering driverless shuttle service on a limited basis starting April 27, giving commuters a chance to try it out while they continue testing it on public streets. For the time being, an attendant will be on board to answer questions and push the emergency stop button if needed.