This subpart applies to the following individuals:

(a) Railroad employees who are assigned to perform service subject to the Hours of Service Act (49 U.S.C. Chapt. 211) during a duty tour, whether or not the person has performed or is currently performing such service, and any person who performs such service.

(b) Railroad employees or agents who:

(1) Inspect, install, repair, or maintain track and roadbed;

(2) Inspect, repair or maintain, locomotives, passenger cars, and freight cars;

(3) Conduct training and testing of employees when the training or testing is required by the FRA's safety regulations; or

(4) Perform service subject to the Transportation of Hazardous Materials laws (49 U.S.C. Ch. 51), or any regulation or order prescribed thereunder;

(c) Railroad managers, supervisors, or agents when they:

(1) Perform the safety-sensitive functions listed in paragraphs (a) and (b) of this section;

(2) Supervise and otherwise direct the performance of the safety-sensitive functions listed in paragraphs (a) and (b) of this section; or

(3) Are in a position to direct the commission of violations of any of the requirements of parts 213 through 241 of this title, or any of the requirements of 49 U.S.C. Ch. 51, or any regulation or order prescribed thereunder.