49 C.F.R. § 236.514 Interconnection of cab signal system with roadway signal system.
Title 49 - Transportation
The automatic cab signal system shall be interconnected with the roadway-signal system so that the cab signal indication will not authorize operation of the train at a speed higher than that authorized by the indication of the roadway signal that governed the movement of a train into a block except when conditions affecting movement of trains in the block change after the train passes the signal.
Title 49: Transportation
PART 236—RULES, STANDARDS, AND INSTRUCTIONS GOVERNING THE INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES
Subpart E—Automatic Train Stop, Train Control and Cab Signal Systems
Standards
§ 236.514 Interconnection of cab signal system with roadway signal system.