When must lighted fusees be displayed by flag protection employees?

The correct answer is that lighted fusees must be displayed by flag protection employees if they see or hear a train approaching. This protocol is crucial for ensuring the safety of both train operations and the workers on or near the tracks. The use of lighted fusees serves as a visual warning to oncoming trains, allowing them to recognize that there is a flagger present and that additional caution is required.

Flag protection employees have a responsibility to alert train crews of potentially hazardous situations, and utilizing lighted fusees when a train is approaching is a key part of that duty. This practice aligns with safety protocols designed to prevent accidents and enhance communication between track workers and train operators.

Other options do not align with standard safety practices. For example, displaying fusees during all train operations would be unnecessary and could lead to confusion, as there are situations where trains operate without requiring such warnings. Similarly, using them only at night or on out-of-service tracks does not provide the necessary safety assurances when an approaching train poses a risk. It is specifically the circumstance of seeing or hearing an approaching train that necessitates the use of lighted fusees for effective flagging and protection.