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 G — Definitions236.70849 C.F.R. § 236.708Block.Last amended: 2017Year: 2026Length: 22 wordsOfficial source Cite as 49 C.F.R. § 236.708 (2026)A length of track of defined limits, the use of which by trains is governed by block signals, cab signals, or both.Previous49 C.F.R. § 236.706Next49 C.F.R. § 236.709