(a) Except as provided in paragraph (b) of this section, this subpart applies to standard gage railroads.
(b) This subpart does not apply to:
(1) A railroad that operates only on track inside an installation which is not part of the general railroad system of transportation; or
(2) Rapid transit operations in an urban area that are not connected with the general railroad system of transportation.
(c) As used in this subpart, carrier means “railroad,” as that term is defined by 49 CFR 232.5