49 C.F.R. § 190.5 Service.
Title 49 - Transportation
(a) Each order, notice, or other document required to be served under this part shall be served personally or by registered or certified mail. (b) Service upon a person's duly authorized representative or agent constitutes service upon that person. (c) Service by registered or certified mail is complete upon mailing. An official U. S. Postal Service receipt from the registered or certified mailing constitutes prima facie evidence of service.
Title 49: Transportation
PART 190—PIPELINE SAFETY PROGRAMS AND RULEMAKING PROCEDURES
Subpart A—General
§ 190.5 Service.