The TPB was created in 1965 by the region's local and state governments to respond to federal highway legislation in 1962 that required the establishment of a "continuing, comprehensive and coordinated" transportation planning process in every urbanized area in the United States. Federal Highway and transit legislation required the establishment of planning bodies, which later became known as Metropolitan Planning Organizations (MPOs), when it became clear that the construction of major transportation projects through and around urban areas needed to be coordinated with local and state jurisdictions.
The TPB is today one of the 384 MPOs across America. According to federal law, an MPO must be designated in every urbanized area with a population over 50,000. The TPB is designated as this region's MPO by the governors of Virginia and Maryland and the mayor of Washington based upon an agreement among the local governments.
The TPB became associated with the Metropolitan Washington Council of Governments (COG) in 1966. COG was established in 1957 by local cities and counties to deal with regional concerns including growth, housing, environment, public health and safety - as well as transportation. Although the TPB is an independent body, its staff is provided by COG's Department of Transportation Planning.