Where:
On any road, but most commonly in mountainous or hilly areas where steep descents occur.

Purpose:
To warn drivers that they may encounter slow-moving heavy vehicles such as trucks, buses, or large transport vehicles travelling downhill at reduced speeds.
These vehicles often move slowly to maintain control and prevent brake failure on steep gradients.

Action:
Reduce your speed and maintain a safe following distance when approaching or driving behind heavy vehicles.
Be patient and avoid overtaking on blind curves or steep sections of the road.
Remember that heavy vehicles require a longer distance to stop or accelerate, particularly when carrying heavy loads.
Exercise extra caution in mountainous regions with sharp bends or limited visibility, and be prepared for sudden braking or slow movement ahead.