The FAST Act converts the long standing Surface Transportation Program (STP) into the Surface Transportation Block Grant Program (STBG). The STBG increases flexibility for states and local governments. Transportation Alternatives Program (TAP) has been combined with STBG. With TAP included in STBG, the program allows up to 50 percent of certain transportation alternatives funding sub-allocated to local areas to be used on any STP-eligible project. The STBG promotes flexibility in state and local transportation decisions and provides flexible funding to best address state and local transportation needs.

Legislation authorizes the expenditure of federal funds for highway related construction and improvements on federal-aid routes and bridges located on or off the federal aid system within the approved urban and urbanized boundaries. In MPOs designated as Transportation Management Areas (TMA), the funds may be used for projects anywhere within the metropolitan planning area. The term "urbanized area" means an area so designated by the Bureau of Census having an urban cluster population of 50,000 or more with boundaries to be fixed by responsible state and local officials in cooperation with each other and subject to approval of the Federal Highway Administration (FHWA). Such boundaries shall as a minimum encompass the entire corporate limits of the urban area.

Under the FAST Act, FHWA apportions funding as a lump sum for each state and then divides that total among apportioned programs. States are to make available obligation authority to urbanized areas with populations over 200,000. In Missouri; Kansas City, St Louis and Springfield are the only MPOs designated as TMAs.