Union City Transit is Union City's own bus system operating within the city limits. Routes are coordinated with BART trains, AC Transit, and the Dumbarton Express to areas outside of the City. Main transfer points are at the Union City BART station and Union Landing Transit Center.

Founded in 1912, the San Francisco Municipal Railway (Muni) is one of America's oldest public transit agencies, and today, it carries over 200 million riders per year. Muni provides transit service within the city and county of San Francisco 24 hours a day, 7 days a week. Operating historic streetcars, modern light rail vehicles, diesel buses, alternative fuel vehicles, electric trolley coaches, and the world-famous cable cars, Muni's fleet is among the most diverse in the world.

A free and frequent shuttle connecting Emeryville's employers and shopping centers with the MacArthur BART station. Service is provided 7 days a week. The Emery Go-Round is funded by commercial property owners in the citywide Emeryville Property Improvement District and is a service of the Emeryville Transportation Management Association.
 

San Mateo County Transit District provides SamTrans bus service throughout San Mateo County and into parts of San Francisco and Palo Alto. The transit district also offers Redi-Wheels paratransit service for persons with disabilities who are unable to ride SamTrans.

Vacaville City Coach operates five local fixed routes, ensuring comprehensive coverage across the City of Vacaville (Solano County).

Most routes begin and end at the Vacaville Transportation Center, and operate for roughly 11 hours a day, Monday through Friday, starting between 7:00 AM and 7:30 AM. Some routes offer Saturday service starting at 8:30 AM. There is no Sunday service.