49 CFR §243.3

1. (a)This part applies to all railroads, contractors of railroads, and training organizations or learning institutions that train safety-related railroad employees except:
   1. (1)Railroads or contractors of 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 § 243.5);
   2. (2)Tourist, scenic, historic, or excursion operations that are not part of the general railroad system of transportation as defined in § 243.5; or
   3. (3)Rapid transit operations in an urban area that are not connected to the general railroad system of transportation.
2. (b)Although the duties imposed by this part are generally stated in terms of the duty of a railroad, each person, including a contractor for a railroad, who performs any duty covered by this part, shall perform that duty in accordance with this part.