Under what condition may a signpost not be changed?

• A. It must be changed.
• B. Need not be changed if a temporary change in conditions results in a temporary change in the boundary location.
• C. It must be changed only if the boundary moves.
• D. It can be changed at any time.

Answer: (B)

The key idea here is that signage for mine boundaries is updated for permanent changes, not for temporary ones. If conditions only cause a boundary to shift for a short period, you don’t need to physically move the signpost right away. Instead, you keep the signpost in its current location and clearly communicate the temporary boundary to everyone involved, using temporary notices or control measures as needed. Once the temporary conditions revert, you can revert to the original boundary marking.

This approach avoids needless sign changes during short-lived disruptions while still maintaining safety and awareness. If the boundary change is permanent, then the signpost must be updated to reflect the new long-term location.