A length of track of defined limits, the use of which is governed by block signals, block limit signals, automatic speed control, or any combination thereof.
A block established between block stations, block limit stations, interlockings, or any combination thereof which must not be occupied by more than one train except as provided in the rules.
Block Signal System
A series of consecutive blocks.
Automatic Block Signal System
A block signal system wherein the use of each block is governed by an automatic block system, the cab signal indicator, or both.
Manual Block Signal System
A block signal system wherein the use of each block is governed by block signals controlled manually, by block limit signals, or both, upon information received by telephone, radio, or other means of communication.