Narrow road warning: road ahead narrows from right side
Road ahead narrows from right side.
Where you will see it
Ahead of a point where the right hand edge comes in and the road loses its width on that side.
What to do
The space that goes is on the right, so oncoming traffic will be closer to you than it has been. Ease off, keep left of the centre line, and give up any thought of passing until the road opens out again.