Officials and members of the media gathered at San Ramon Bishop Ranch Tuesday morning for a historical moment -- the state's first testing of shared autonomous vehicles on public streets.

The implementation of the EasyMile shuttles is part of Contra Costa County's larger vision of future transportation, in particular solving the "first and last mile" problem of connecting residents to the Bart station.

"Imagine a day when you have door to door service, that's very, very inexpensive," said Randell Iwasaki, executive director of Contra Costa Transportation Authority, which is leading the project in conjunction with GoMentum Station. "We can get to not only that first and last mile issue, but with this technology we can get to the under-served parts of our community."

The shuttles had been undergoing tests on the Bishop Ranch site since last year, but after the California Department of Motor Vehicles recently granted permission for the vehicles to travel on public roads, the next phase of testing can begin. This new phase, said San Ramon transportation manager Lisa Bobadilla, will include finding a way to allow the autonomous vehicles to communicate with stop lights.

"For Bishop Ranch, it's important because this is the first and last mile to a Bart station, or to here and San Ramon, the City Center," Bobadilla said. "So it's going to be really important, they're going to use this shuttle to transport tenants from all of these office buildings to the new City Center."

That's the short-term vision, she said -- in the long-term, officials hope these shuttles can be used all over Contra Costa to connect residents to Bart.

Residents and Bishop Ranch tenants still have a while to wait before they're actually using the shuttles regularly, though.

From a city perspective, Mayor Bill Clarkson, who was also at the event, said that the shuttles could also reduce the need for parking -- currently, parking structures cost $75,000 per parking space.

Two vehicles were present at the Tuesday event: a stationary one that served as a ceremonial backdrop, and one in operation that carried attendees in a loop, traveling briefly onto a side street and then back to the Bishop Ranch parking lot. Jolynn Williams operated the shuttle -- however, they are designed to be completely autonomous.

For example, at a site like this, said Joseph Holmes from Easy Mile, they could potentially have a fleet of 15 with perhaps three roaming attendants. Each shuttle can hold about 12 people.

While the shuttles have the capability to travel at 30 mph, on average they operate at 10-12 mph, Holmes said.

"We're not looking to be replacing the transit vehicles today," he said. "We're actually looking to enhance the existing transit network by actually increasing the ridership on those existing services by this door-to-door transportation."

The shuttles operate in different modes -- for Tuesday's tour, the vehicle was pre-programmed to follow its route, but they will also be able to connect to users "on-demand" via a phone application, Holmes said.

Iwasaki said that residents of San Ramon and Danville had expressed the need for a better connection to the Bart station, leading them to look into autonomous vehicle options. They selected Bishop Ranch as a test site because of its innovative leaders, he said, as well as the fact that the site has been seeking a feeder system to nearby buses.

Even if it takes 200 cars off the road, he said, "that is congestion relief."

The goal is to get the riding price down to 10-15 cents per mile, he said. For people who only need to drive a few miles to get to work, this service could make a lot more sense than actually owning a car, he said.

"We're not testing a bright, shiny object," Iwasaki said during his opening comments. "We're actually trying to test a solution to problems that have plagued us over the years."