What does an illuminated light over the route request buttons represent?

An illuminated light over the route request buttons indicates a successful registration of the requested route. This visual cue helps train operators confirm that their input has been acknowledged by the train control system. It serves as an assurance that the route request has been processed correctly, allowing the operator to proceed with confidence that the train will follow the requested path.

Understanding this signal is crucial for train operators as the accuracy of route registration is vital for maintaining safe and efficient train operations. If the light were not illuminated, it would imply that the system has not recorded the request properly, which could lead to operational errors and potentially jeopardize safety on the rail network.