US lawFederal (United States)RegulationsTitle 49 CFR — TransportationChapter II — FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATIONPart 236 — RULES, STANDARDS, AND INSTRUCTIONS GOVERNING THE INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCESSubpart C — Interlocking236.37949 C.F.R. § 236.379Route locking.Last amended: 2017Year: 2026Length: 37 wordsOfficial source Cite as 49 C.F.R. § 236.379 (2026)Route locking or other type of switch locking shall be tested when placed in service and thereafter when modified, disarranged, or at least once every two years, whichever shall occur first. [49 FR 3385, Jan. 26, 1984]Previous49 C.F.R. § 236.378Next49 C.F.R. § 236.380