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 E — Automatic Train Stop, Train Control and Cab Signal Systems236.56449 C.F.R. § 236.564Acknowledging time.Last amended: 2017Year: 2026Length: 14 wordsOfficial source Cite as 49 C.F.R. § 236.564 (2026)Acknowledging time of intermittent automatic train-stop device shall be not more than 30 seconds.Previous49 C.F.R. § 236.563Next49 C.F.R. § 236.565