49 U.S.C. § 13301 Powers
(a) General Powers of Secretary.—Except as otherwise specified, the Secretary shall carry out this part. Enumeration of a power of the Secretary in this part does not exclude another power the Secretary may have in carrying out this part. The Secretary may prescribe regulations in carrying out this part.
(b) Obtaining Information.—The Secretary may obtain from carriers providing, and brokers for, transportation and service subject to this part, and from persons controlling, controlled by, or under common control with those carriers or brokers to the extent that the business of that person is related to the management of the business of that carrier or broker, information the Secretary decides is necessary to carry out this part.
(c) Subpoena Power.—(1) By secretary.—The Secretary may subpoena witnesses and records related to a proceeding under this part from any place in the United States, to the designated place of the proceeding. If a witness disobeys a subpoena, the Secretary, or a party to a proceeding under this part, may petition a court of the United States to enforce that subpoena. (2) Enforcement.—The district courts of the United States have jurisdiction to enforce a subpoena issued under this section. Trial is in the district in which the proceeding is conducted. The court may punish a refusal to obey a subpoena as a contempt of court.
(d) Testimony of Witnesses.—(1) Procedure for taking testimony.—In a proceeding under this part, the Secretary may take the testimony of a witness by deposition and may order the witness to produce records. A party to a proceeding pending under this part may take the testimony of a witness by deposition and may require the witness to produce records at any time after a proceeding is at issue on petition and answer. (2) Subpoena.—If a witness fails to be deposed or to produce records under paragraph (1) of this subsection, the Secretary may subpoena the witness to take a deposition, produce the records, or both. (3) Depositions.—A deposition may be taken before a judge of a court of the United States, a United States magistrate judge, a clerk of a district court, or a chancellor, justice, or judge of a supreme or superior court, mayor or chief magistrate of a city, judge of a county court, or court of common pleas of any State, or a notary public who is not counsel or attorney of a party or interested in the proceeding. (4) Notice of deposition.—Before taking a deposition, reasonable notice must be given in writing by the party or the attorney of that party proposing to take a deposition to the opposing party or the attorney of record of that party, whoever is nearest. The notice shall state the name of the witness and the time and place of taking the deposition. (5) Transcript.—The testimony of a person deposed under this subsection shall be taken under oath. The person taking the deposition shall prepare, or cause to be prepared, a transcript of the testimony taken. The transcript shall be subscribed by the deponent. (6) Foreign country.—The testimony of a witness who is in a foreign country may be taken by deposition before an officer or person designated by the Secretary or agreed on by the parties by written stipulation filed with the Secretary. A deposition shall be filed with the Secretary promptly.
(e) Witness Fees.—Each witness summoned before the Secretary or whose deposition is taken under this section and the individual taking the deposition are entitled to the same fees and mileage paid for those services in the courts of the United States.
(f) Powers of Board.—For those provisions of this part that are specified to be carried out by the Board, the Board shall have the same powers as the Secretary has under this section.