[2] They are responsible for administering the Measure I half-cent tax which voters in San Bernardino County, California, passed most recently in 2004.

Every city and county supervisor is provided one seat on the board, and it also includes a nonvoting member from the California Department of Transportation's (Caltrans) District 8.

[15][16][17] The West Valley Connector, also known as the sbX Purple Line,[18] is a 35-mile long (56 km) bus rapid transit project spearheaded by the SBCTA that will connect Pomona with Fontana.

[19] The first phase is a 19-mile long (31 km) segment that will run along Holt Boulevard to Ontario International Airport and Metrolink’s Rancho Cucamonga station.

[22] Initially, The Boring Company proposed constructing a single 2.8-mile (4.5 km) tunnel similar to the Las Vegas Convention Center Loop that would cost $60 million.

[26] In October [27] 2024, the proposed route follows a reversed L-shaped alignment consisting of the Rancho Cucamonga Metrolink Station, Milliken Avenue, East Airport Drive towards Ontario airport The SBCTA is in the process of double-tracking Metrolink's San Bernardino Line from CP Lilac to Rialto station to increase capacity and frequency within San Bernardino County.

[33] The trainset is expected to be in operation by 2024[34] SBCTA administers the County's van pool Commuter service called SB Loop.

Averaging 119,400 trips per quarter in 189 vehicles [35] In order to reduce congestion, the SBCTA implemented the Freeway Service Patrol (FSP), whose purpose is to tow stranded motorists within the urbanized area of San Bernardino County.

The SBCTA requires complete streets within San Bernardino County when cities apply for roadway expansion grants.

The city of Rialto has expressed in expanding the bike trail to SBCTA, once Union Pacific abandons the rail service in the eastern 2.5 miles of the subdivision.