49 CFR 1503.647 - Subpoenas.
(a) Request for subpoena. A party may obtain a subpoena to compel the attendance of a witness at a deposition or hearing, or to require the production of documents or tangible items, from the ALJ who is assigned to the case, or, if no ALJ is assigned or the assigned law judge is unavailable, from the chief ALJ. The party must complete the subpoena, stating the title of the action and the date and time for the witness' attendance or production of documents or items. The party who obtained the subpoena must serve the subpoena on the witness or the custodian of the documents or tangible items sought to be produced.
(b) Motion to quash or modify the subpoena. A party, or any person upon whom a subpoena has been served, may file a motion to quash or modify the subpoena at or before the time specified in the subpoena for compliance. The applicant must describe, in detail, the basis for the application to quash or modify the subpoena including, but not limited to, a statement that the testimony, document, or tangible evidence is not relevant to the proceeding, that the subpoena is not reasonably tailored to the scope of the proceeding, or that the subpoena is unreasonable and oppressive. A motion to quash or modify the subpoena will stay the effect of the subpoena pending a decision by the ALJ on the motion.
(c) Enforcement of subpoena. Upon a showing that a person has failed or refused to comply with a subpoena, a party may apply to the U.S. district court having jurisdiction to seek judicial enforcement of the subpoena in accordance with 49 U.S.C. 46104.