49 C.F.R. § 1122.5 – Procedural rules.

(a) After notifying the party subject to Preliminary Fact-Finding that Preliminary Fact-Finding has commenced, the Board staff shall, within a reasonable period of time, either:
1. (1) Conclude Preliminary Fact-Finding and notify any parties involved that the process has been terminated; or
2. (2) Recommend to the Board that a Board-Initiated Investigation is warranted.
(b) Not later than 30 days after commencing a Board-Initiated Investigation, the Investigating Officer(s) shall provide the parties under investigation a copy of the Order of Investigation. If the Board adds or removes Investigating Officer(s) during the course of the Board-Initiated Investigation, it shall provide written notification to the parties under investigation.
(c) Not later than 275 days after issuance of the Order of Investigation, the Investigating Officer(s) shall submit to the Board and the parties under investigation:
1. (1) Any recommendations made as a result of the Board-Initiated Investigation; and
2. (2) A summary of the findings that support such recommendations.
(d) Not later than 90 days after receiving the recommendations and summary of findings, the Board shall decide whether to dismiss the Board-Initiated Investigation if no further action is warranted or initiate a Formal Board Proceeding to determine whether any provision of 49 U.S.C. Subtitle IV, Part A, has been violated in accordance with section 12 of the Surface Transportation Board Reauthorization Act of 2015. The Board shall dismiss any Board-Initiated Investigation that is not concluded with administrative finality within one year after the date on which it was commenced.
(e) A Formal Board Proceeding commences upon issuance of a public Order to Show Cause. The Order to Show Cause shall state the basis for, and the issues to be considered during, the Formal Board Proceeding and set forth a procedural schedule.