US lawFederal (United States)RegulationsTitle 49 CFR — TransportationChapter II — FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATIONPart 234 — GRADE CROSSING SAFETYSubpart D — Maintenance, Inspection, and Testing234.25149 C.F.R. § 234.251Standby power.Last amended: 2017Year: 2026Length: 10 wordsOfficial source Cite as 49 C.F.R. § 234.251 (2026)Standby power shall be tested at least once each month.Previous49 C.F.R. § 234.249Next49 C.F.R. § 234.253