49 C.F.R. § 242.121 – Knowledge testing.

(a) Each railroad shall adopt and comply with a program that meets the requirements of this section. When any person including, but not limited to, each railroad, railroad officer, supervisor, and employee violates any requirement of a program which complies with the requirements of this section, that person shall be considered to have violated the requirements of this section.
(b) After the pertinent date specified in § 242.105(d) or (e), each railroad, prior to initially certifying or recertifying any person as a conductor for any type of service, shall determine that the person has, in accordance with the requirements of this section, demonstrated sufficient knowledge of the railroad's rules and practices for the safe movement of trains.
(c) In order to make the knowledge determination required by paragraph (b) of this section, a railroad shall have procedures for testing a person being evaluated for certification as a conductor that shall be:
1. (1) Designed to examine a person's knowledge of the railroad's operating rules and practices for the safe movement of trains;
2. (2) Objective in nature;
3. (3) Administered in written or electronic form;
4. (4) Cover the following subjects:
  1. (i) Safety and operating rules;
  2. (ii) Timetable instructions;
  3. (iii) Compliance with all applicable Federal regulations;
  4. (iv) Physical characteristics of the territory on which a person will be or is currently serving as a conductor; and
  5. (v) Use of any job aid that a railroad may provide a conductor;
5. (5) Sufficient to accurately measure the person's knowledge of the covered subjects; and
6. (6) Conducted without open reference books or other materials except to the degree the person is being tested on his or her ability to use such reference books or materials.
(d) The conduct of the test shall be documented in writing and the documentation shall contain sufficient information to identify the relevant facts relied on for evaluation purposes.
(e) For purposes of paragraph (c) of this section, the railroad must provide the person(s) being tested with an opportunity to consult with a supervisory employee, who possesses territorial qualifications for the territory, to explain a question.
(f) The documentation shall indicate whether the person passed or failed the test.
(g) If a person fails to pass the test, no railroad shall permit or require that person to function as a conductor prior to that person's achieving a passing score during a reexamination of the person's knowledge.