{"data":{"id":"us/49-cfr-236.307","jurisdiction":"us","citation":"49 CFR 236.307","heading":"Indication locking.","body":"Indication locking shall be provided for operative approach signals of the semaphore type, power-operated home signals, power-operated switches, movable-point frogs and derails, and for all approach signals except light signals, all aspects of which are controlled by polar or coded track circuits or line circuits so arranged that a single fault will not permit a more favorable aspect than intended to be displayed.","path":["Title 49—Transportation","Subtitle B—Other Regulations Relating to Transportation","CHAPTER II—FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION","PART 236—RULES, STANDARDS, AND INSTRUCTIONS GOVERNING THE INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES","Subpart C—Interlocking"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-49.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:26:34Z","sha256":"c87cf5a6e3b0f8e66982fd1d2f59dc65f8004d1351143cd7e011fe202bbf3d48","source_id":"us-cfr","stale":true,"prev":"us/49-cfr-236.306","next":"us/49-cfr-236.308"},"notice":"GroundRules: Original legal text. Not legal advice."}