The District is a multi-agency transit organization that includes CalTrain, a growing commuter rail service that serves the region from San Francisco to Silicon Valley; San Mateo County Transit (SamTrans), a changing bus and paratransit system that is a multi-modal mobility service provider, and the San Mateo County Transportation Authority (TA), a funding agency that supports transit and transportation projects.

Mission: To supply the public with a high-quality, safe and efficient transportation system that should enhance quality of life by increasing access and mobility, reducing congestion, improving the environment and promoting economic vitality.