Communication systems for railway traffic control

CONTROL of railway traffic from a central location requires the transfer of large amounts of information between the central location and many points along the railroad. The number of wayside information points depends on the type of signaling installed, which in turn depends on the type and amount of traffic handled by the railroad. Certainly, effective communication is required with all locations where track switches and controlled signals are situated. Information must also be available from a sufficient number of points to keep the dispatcher informed about the location and progress of all trains.