What type of signal is indicated by moving the hand or light in a to-and-fro motion?

The signal indicated by moving the hand or light in a to-and-fro motion is specifically designed to communicate a "Stop" command. This type of signaling is universally recognized and serves as an immediate warning to train operators that they must halt their trains. The distinguishing characteristic of this signal is its back-and-forth motion, which differentiates it from other signals that might indicate continued movement or reduced speed.

Understanding this signal is critical for ensuring safety on the railways, as stopping in response to such an indication can prevent potential accidents or unsafe situations on the track. Operators are trained to recognize and respond to this signaling pattern promptly to maintain operational safety protocols. This type of signal effectively captures attention and conveys urgency, which is essential in the fast-paced environment of train operations.