What are "hand signals" used for?

Hand signals are primarily used for crew communication when verbal methods are unsuitable, making it essential in environments where noise may interfere with spoken commands, such as on a moving train. These signals provide a reliable visual means for crew members to convey important information or instructions quickly and effectively, ensuring safety and coordination among team members, especially in situations where it's impossible to hear or be heard.

While directing passengers to their seats, indicating train speeds, and giving instructions to ticket collectors may involve some form of signaling or communication, these activities do not typically rely on the specific use of hand signals as a standardized method. Hand signals are a critical component of operational safety in rail transport, designed specifically to facilitate clear communication among crew members in a variety of circumstances.