What is a "flagging" procedure?

The "flagging" procedure refers to a method of directing train movements using visual signals and personnel. This procedure typically involves the use of flags, lights, or other visual signals to communicate instructions to train operators, especially in situations where regular signaling systems may not be available or are under maintenance. Personnel on the ground, known as flaggers, are crucial for ensuring safety and proper movement through active work zones or areas with potential hazards.

Using flagging is essential during specific operational scenarios, such as maintenance work, emergencies, or other conditions where trains might be on unusual schedules or paths. Flaggers are trained to effectively control train traffic and help prevent accidents by clearly communicating with train crews in a way that is easily understood amidst various environmental factors.