(a) Except as provided in paragraph (b) of this section, this part applies to all—

(1) Passenger rail operations that operate intercity or commuter passenger train service on the general railroad system of transportation; and

(2) Passenger rail operations that operate commuter or other short-haul rail passenger train service in a metropolitan or suburban area (as described by 49 U.S.C. 20102(2)), including public authorities operating passenger train service.

(b) This part does not apply to:

(1) Rapid transit operations in an urban area that are not connected to the general railroad system of transportation;

(2) Tourist, scenic, historic, or excursion operations, whether on or off the general railroad system of transportation;

(3) Operation of private cars, including business/office cars and circus trains; or

(4) Railroads that operate only on track inside an installation that is not part of the general railroad system of transportation (i.e., plant railroads, as defined in § 270.5).