What is one characteristic of an effective warning line system?

An effective warning line system is designed to indicate the safe work area, ensuring that workers are aware of their limits and the boundaries of hazardous zones. This characteristic is crucial for maintaining safety on a job site, as it visually communicates where personnel can safely work without being exposed to potential fall hazards or other dangers. By clearly marking the safe work area, workers are more likely to stay within designated zones, reducing the risk of accidents and injuries.

The other characteristics listed, while they may have relevance in different contexts, do not directly relate to the primary purpose of a warning line system, which is to provide a clear visual demarcation of safe and unsafe areas.