The Federal Transit Administration (FTA) is the counterpart to FRA for regulation of tranist properties. However, FTA has a Memorandum of Understanding (MOU) with FRA that in the event of a need for Federal resolution of a rail safety issue FRA will provide necessary oversite. In the MOU FRA's rail safety expertise is expressly noted. FTA spends most of its efforts in funding and promoting such transit systems.
In California the State Public Utilites Commission exercises safety oversite jurisdiction over public guideways (Ref. P.U. Code Sec. 99152) which covers BART and light rail systems. The Commission's safety regulations for these types of systems can be found in the agency's General Orders on its website (CPUC). Other States also exercise safety jurisdiction over rail transit system; the State of New York over NY City subways.