The Capital Area Rural Transportation System (CARTS) is a political subdivision of Texas which was originally organized in 1978. Subsequently authorized by Texas Transportation Code Chapter 458 as a Rural Transit District (RTD), it is eligible for formula apportionment of state and federal funds for transit services. Since its establishment, CARTS has served as an RTD for the non-urbanized areas of nine counties in central Texas, including Bastrop, Blanco, Burnet, Caldwell, Fayette, Hays, Lee, Travis, and Williamson Counties. In 2012, the U.S. Census Bureau designated San Marcos/Redwood as an urbanized area (UZA) based on the results of the 2010 U.S. Census. As a result of the statutorily required Transportation Conference convened by the affected local governments (City of San Marcos, City of Martindale, Comal, Caldwell, and Hay counties) CARTS was selected to assume the direct recipient status for the UZA and formed an Urban Transit District in 2013.

The CARTS family of interconnected services includes general public demand-response paratransit (Country Bus) throughout its rural district, and a scheduled regional bus service (Interurban Coach) that connects Austin and 17 surrounding cities, and serves eight CARTS stations located in Austin, Bastrop, Georgetown, Marble Falls, Round Rock, San Marcos, Smithville, and Taylor. The CARTS stations also serve as Greyhound ticketing. Interurban Express routes serve commuters on routes operating between Bastrop and Austin between Austin and San Marcos. CARTS fixed route municipal transit operations in Georgetown (Go-Geo), San Marcos (THE BUS) and a flex fixed route in Bastrop (Municipal Bus) provide local mobility options in those towns and connect to the CARTS regional Interurban routes.

Under the Regional Mobility Agreement (ILA) with Capital Metro, CARTS provides transit services for Hornsby Bend, Georgetown, Manor, and Jonestown/Lago Vista as well as a collaborative commuter service between Elgin and Austin.

CARTS is governed by a board made up of a member from each of the nine county Commissioners Courts and an appointed representative of the San Marcos City Council.