US lawFederal (United States)RegulationsTitle 49 CFR — TransportationChapter II — FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATIONPart 220 — RAILROAD COMMUNICATIONSSubpart B — Radio and Wireless Communication Procedures220.4549 C.F.R. § 220.45Radio communication shall be complete.Last amended: 2017Year: 2026Length: 38 wordsOfficial source Cite as 49 C.F.R. § 220.45 (2026)Any radio communication which is not fully understood or completed in accordance with the requirements of this part and the operating rules of the railroad, shall not be acted upon and shall be treated as though not sent.Previous49 C.F.R. § 220.43Next49 C.F.R. § 220.47