The region's transit agencies report transit fleet conditions to the Federal Transit Administration's (FTA) National Transit Database (NTD), by either rail vehicle or bus. Rail vehicles include hybrid rail and trolleys, heavy rail (i.e., subway), and regional rail passenger cars and locomotives.

Four different agencies provide transit service to the region. SEPTA provides bus and rail service to all five southeastern Pennsylvania counties and has several commuter rail lines that terminate outside this service area, in New Castle County, Delaware; and Mercer County, New Jersey. The Port Authority Transit Corporation (PATCO) operates a passenger rail line connecting Philadelphia with Camden County. New Jersey Transit (NJ Transit) runs buses throughout the four southern New Jersey counties and into Philadelphia, a hybrid rail line connecting Camden and Mercer counties, and two commuter rail lines connecting Philadelphia and Atlantic City, and Mercer County to New York City. Finally, Pottstown Area Rapid Transit (PART) provides bus service throughout Pottstown and into several neighboring municipalities in Montgomery and Chester counties.

All NJ Transit services are classified as being in the NJ Counties Subregion, because they mostly do not cross over to the Pennsylvania side of the region, and NJ Transit only reports statewide figures to the NTD.