49 CFR § 31.23 - Subpoenas for attendance at hearing.
(c) A party seeking a subpoena shall file a written request therefor not less than 15 days before the date fixed for the hearing unless otherwise allowed by the ALJ for good cause shown. Such request shall be accompanied by a proposed subpoena, which shall specify and documents to be produced and shall designate the witnesses and describe the address and location thereof with sufficient particularity to permit such witnesses to be found.
(d) The subpoena shall specify the time and place at which the witness is to appear and any documents the witness is to produce.
(f) A party or the individual to whom the subpoena is directed may file a motion to quash the subpoena within ten days after service or on or before the time specified in the subpoena for compliance if it is less than ten days after service. If the ALJ has not acted on such a motion by the return date, such date shall be suspended pending the ALJ's final action on the motion.