What is the purpose of a cab signal?

The purpose of a cab signal is to show permissible speed in the engine control compartment. Cab signals are an important safety feature designed to provide the train operator with real-time information about speed limits and track conditions directly in the cab. This system allows conductors to operate trains more safely by ensuring they are aware of any changes in permissible speed without having to rely solely on traditional wayside signals.

Cab signals enhance situational awareness and improve response times by delivering critical updates to the operators as they approach areas with speed restrictions or other operational considerations. This functionality is vital for maintaining safe operations on the railroad and helps prevent accidents that may arise from over-speeding or misjudgment of track conditions.