Falling Rocks Sign
The falling rocks sign warns that loose rocks may fall onto the road from adjacent cliff faces or rock cuts. Drivers must watch for rocks on the pavement and be prepared to swerve or stop.
Last updated: April 4, 2026
In areas where roads have been cut through rock, the exposed cliff faces can shed loose material onto the road surface. The falling rocks sign alerts drivers that this is an active hazard zone. Rocks may be small pebbles or large boulders. Rain, freeze-thaw cycles, and spring melt increase the likelihood of rock falls.
Quick Facts
Type
Warning Sign
Shape
Diamond
Colours
Yellow background with black falling rock symbol
In this guide
What does the Falling Rocks Sign mean?
In areas where roads have been cut through rock, the exposed cliff faces can shed loose material onto the road surface. The falling rocks sign alerts drivers that this is an active hazard zone. Rocks may be small pebbles or large boulders. Rain, freeze-thaw cycles, and spring melt increase the likelihood of rock falls.
What to do when you see it
Reduce speed and scan the road ahead for debris. Do not stop under rock faces. If you see a rock on the road, avoid it if safely possible or stop if the rock is too large to avoid. Report large rocks or fresh rock fall to the Ontario Ministry of Transportation by calling 511.
Where you'll see it in Ontario
Falling rocks signs are common on highways through the Canadian Shield in Northern Ontario, on Trans-Canada Highway sections through the north, on the Highway 11/17 corridor, and on any road built through rocky terrain with exposed cliff faces.
G1 test relevance
This sign is tested as part of general warning sign knowledge. The expected driver response is to slow down and watch the road surface for debris, the same general response required for all warning signs.
Common mistakes drivers make
Stopping on the road directly beneath a rock face to look at debris or take a picture is dangerous. Drivers should also not straddle rocks in the road: stop safely or go around if the lane is clear.
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