County Connection

AC Transit began operating local bus service under contract in central Contra Costa County in the 1970s after the coming of BART. Service began in Concord on September 8, 1975; in Pleasant Hill on December 8, 1975; and in Moraga and Orinda on September 13, 1976. Walnut Creek began operating a downtown shuttle route connecting to BART in December 1974.

On March 27, 1980, the Central Contra Costa Transit Authority (CCCTA) was created by a joint powers agreement between the cities of Clayton, Concord, Lafayette, Martinez, Moraga, Pleasant Hill, and Walnut Creek, plus the County of Contra Costa. The agency took over operations of the Walnut Creek system on July 1, 1980; by 1982, it had seven routes and twelve minibuses. The CCCTA originally planned to take over the other services in its district from AC Transit in August 1981. However, slow delivery of the buses and heavy rains that slowed construction of a maintenance facility delayed this until 1982.

A Walnut Creek writer, Elizabeth Tenney, won a contest in early 1982 to create a slogan for the CCRTA system. Her slogan, "The County Connection", was adopted as the system branding. The CCCTA took over local bus service in its district from AC Transit on June 7, 1982, with a fleet of 24 new Gillig buses. (AC Transit continued to operate express bus service that functioned as feeder service for BART.) At that time, the Walnut Creek routes had 2,500 daily riders, while the routes taken over from AC Transit had 8,000 daily riders. Several routes were consolidated with the takeover, while a new Martinez–Concord–Clayton route was added.

County Connection took over the operations of three private paratransit providers in 1990 to form its paratransit service, branded as LINK. In 1994, the agency took over the BART express bus feeder service.

As of May 2020, the County Connection operates 25 weekday routes (three of which also operate on weekends), seven weekend-only routes, and 19 school tripper routes within central Contra Costa County. All routes, with the exception of some of the 600-numbered series select service trips, connect with regional train service, primarily BART, in addition to ACE in Pleasanton and Amtrak, including Amtrak California's Capitol Corridor and Gold Runner services in Martinez. Among its 30 weekday routes, the County Connection operates seven express routes (Routes 91X—98X). With support from the city of Walnut Creek, the County Connection also operates a free downtown circulator with trolley livery (Route 4) with service between Walnut Creek and Broadway Plaza.

The fleet consists of 121 accessible buses and 63 paratransit vans.

Bus service does not operate on New Year's Day, Memorial Day, Labor Day, Thanksgiving, and Christmas.

Weekdays

Weekday service is provided on all routes except 300-numbered series routes, which operate only on weekends. 600-numbered series routes are select service trips convenient to area schools and operate on school days, with service timed to school bell times.