What do you do when you see this traffic sign?

You answered correctly with reducing your speed and refraining from overtaking. This sign warns that the road narrows ahead. When you see it, you must slow down because the reduced road width can create hazards, and overtaking is unsafe due to limited space.

Stopping before the road narrows is not required unless necessary for safety or traffic control—there is no general rule that you must stop just because of the narrowing. The key is to proceed carefully with a lower speed and avoid overtaking to prevent accidents in the narrower section. This ensures smooth and safe traffic flow.