Maria Korbay of Tri Delta Transit said the initiative focuses on areas with low ridership that were hard to service with a traditional bus.

"There's a lot of cul-de-sacs, a lot of dead ends, and you just can't get a 40-foot bus down those kind of roads, nor does anybody want one lumbering down at 5 in the morning," said Korbay.

She said the agency was inspired by a successful service in Sacramento.

Other counties throughout the Bay Area have launched similar services with mixed results.

In the Linda Mar neighborhood in Pacifica, riders can request a shuttle ride for $2.25 through the SamTrans OnDemand smartphone app.

The Santa Clara Valley Transportation Authority's on-demand FLEX service pilot program launched and ended in 2016. Transportation officials there say the program did not catch on.

Meanwhile, the Alameda-Contra Costa Transit District's Flex program had some success when it launched in 2016. In March 2018, the board of directors voted to continue the Flex service beyond its initial pilot year.

Sara Hossaini and Hope McKenney contributed to this report.