When should the word "Void" be written on the Track Authority form?

The word "Void" should be written on the Track Authority form when limits or instructions have been changed because this indicates that the previously issued authority is no longer valid. This is crucial for maintaining safety and ensuring that all train crews and personnel are aware of the most current instructions regarding the use of track authority. By marking it as "Void," it eliminates any confusion that might arise from miscommunication about outdated or altered instructions.

In cases where a train is stopped, limits being reported clear, or crew changes occur, the original Track Authority may still be in effect, and thus does not require the "Void" designation. The emphasis on changing limits or instructions highlights the importance of continuous communication and clarity in rail operations to prevent potential hazards.