In plain English
You can't see far enough ahead to pass safely here — hidden dips, bends or junctions. The ban ends where you see a sign with a diagonal stripe.
Where you'll see it
On roads with blind summits, tight bends, or a history of head-on collisions.
The common trap
The red car is the one doing the overtaking. Red = the move that's banned, black = the car minding its own business.
Memory anchor
Two cars in the ring: the red one is breaking out of line — and red means no.