The project is spearheaded by the Contra Costa Transportation Authority (CCTA), though most of the funding comes from the owners of the Bishop Ranch property.
Randy Iwasaki, the executive director of the CCTA, suggests that, if anything, these vehicles are too cautious. He remembers the shuttle coming to an abrupt stop during a trial run.
"It was a windy day, and a plastic bag flew in front of the vehicle," Iwasaki said.
To drive on a public road in California, an autonomous vehicle must have a steering wheel, a brake and a driver who can take over. These shuttles have none of those.
At first, the shuttles will operate only inside the Bishop Ranch property. But public roads cut through the complex. Eventually, pending DMV approval, the shuttles will use those roads.
"Really it's just crossing from one parking lot to another," Iwasaki said.
For now, a "safety attendant" will ride with the passengers. The attendant can make emergency stops or answer questions about the shuttle. Project managers are hoping that in the long run riders will feel comfortable enough to use the buses without an attendant.
Darryl Taylor, who drives a public bus from the Walnut Creek BART station to the Bishop Ranch complex, says he's not too worried about a future where robots take over the driving jobs.
"I know it's coming," Taylor said. "Hopefully by the time it comes, I'll be retired."