49 C.F.R. § 10.43

Within ten days (excluding Saturday, Sunday, and legal holidays) of the receipt in accordance with § 10.41 of a request by an individual to amend a record pertaining to him, the receipt of the request is acknowledged in writing. If a determination is made to correct the record as requested, the correction is promptly made. If a determination is made not to correct a record the individual is informed promptly of the right to appeal in accordance with subpart F. If an appeal of a refusal to correct a record is in accordance with subpart F, a determination whether to correct the record is made within thirty days (excluding Saturday, Sunday, and legal holidays) of the receipt of the appeal unless, for good cause shown the Administrator concerned, or in the case of the Office of the Secretary, the General Counsel, extends such period. Where an extension is taken, the party taking the appeal is promptly notified of such fact.