Where:
On any road, but especially in mountainous or hilly areas, along cliffs, cuttings, or steep slopes where loose rocks or debris may fall onto the road.
These signs are often placed where rockslides or falling stones are common due to natural erosion or weather conditions.

Purpose:
To warn drivers that rocks or debris may fall onto the carriageway from either the left or right-hand side.
Falling rocks present a serious hazard, as they can appear suddenly and cause accidents, damage vehicles, or block the road.
The risk is higher during or after rain, storms, or freeze-thaw conditions, which can loosen rocks and increase the likelihood of rockfalls.

Action:
Reduce your speed so you can stop safely if rocks are on the road.
Increase your alertness, scanning the road ahead and the slopes beside the road for loose stones or debris.
Be prepared for sudden stops, especially in areas with curves or reduced visibility.
Increase following distance from vehicles ahead to allow time to react if they encounter falling rocks.
Exercise extra caution during or after rain, as the road surface may be slippery and stopping distances will be longer.
Avoid stopping unnecessarily near the cliff edge or directly under overhanging rocks.
If rocks are on the road, drive around them safely if possible, or stop and report the hazard to authorities if necessary.