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 A — Rules and Instructions: All Systems236.149 C.F.R. § 236.1Plans, where kept.Last amended: 2017Year: 2026Length: 28 wordsOfficial source Cite as 49 C.F.R. § 236.1 (2026)As required for maintenance, plans shall be kept at all interlockings, automatic signals and controlled points. Plans shall be legible and correct. [49 FR 3382, Jan. 26, 1984]Next49 C.F.R. § 236.2