49 U.S.C. § 20112: Enforcement by the Attorney General

to enjoin a violation of, or to enforce, this part, except for section 20109 of this title , or a railroad safety regulation prescribed or order issued by the Secretary; to collect a civil penalty imposed or an amount agreed on in compromise under section 21301, 21302, or 21303 of this title; or to enforce a subpoena, request for admissions, request for production of documents or other tangible things, or request for testimony by deposition issued by the Secretary under this part. Except as provided in paragraph (2) of this subsection, a civil action under this section may be brought in the judicial district in which the violation occurred or the defendant has its principal executive office. If an action to collect a penalty is against an individual, the action also may be brought in the judicial district in which the individual resides. A civil action to enforce a subpena issued by the Secretary or a compliance order issued under section 20111(b) of this title may be brought in the judicial district in which the defendant resides, does business, or is found.