What does the passing prohibited sign mean?

This sign appears at the start of a stretch of two-way road. What does it forbid?

Overtaking other vehicles anywhere along this stretch

The ban covers passing, whatever you are passing and however slowly it is moving. It does not stop you crossing the centre line to turn left into a road or driveway, because that is a turn and not a pass.

This sign is posted, a slow truck is ahead of you, and the road beyond the truck looks clear. What are you allowed to do?

Stay behind the truck until the restriction ends

The restriction is based on what you cannot see, not on what looks clear from where you are sitting, so an apparently empty road ahead is not permission. These stretches almost always hide a crest, a bend or a concealed entrance where an oncoming vehicle appears with no warning at all.

You are closing on a slow vehicle and this sign appears at the roadside just as you were about to pull out. What do you do?

Stay behind and drop back to a safe following gap

The restriction starts at the sign, so a pass you have not yet begun is a pass you do not make. It is posted where the view ahead is shorter than the distance a pass really needs, which is longer than most drivers picture. Dropping back matters too, because sitting close behind removes the view you will want when a legal stretch arrives.

You are behind a slow truck on a two-lane road when this sign appears at the roadside. The oncoming lane looks empty from where you are sitting. What does the sign require?

Stay behind until the restriction ends, whatever the oncoming lane looks like

The ban is posted where you cannot see far enough for a pass to be finished safely, usually a crest, a bend or a hidden entrance. The clear stretch you can see is not the problem, the part you cannot see is. A driver waving you past is guessing, and the pass stays your responsibility.

You are behind a slow vehicle in a stretch marked by this sign, and the oncoming lane looks empty as far as you can see. May you overtake?

No, the ban holds regardless of what you can see

The sign is placed exactly where the view is shorter than it feels, usually before a crest or a bend that hides an approaching vehicle until it is very close. Following a slow vehicle for another minute costs far less than meeting one head-on.

The line down the centre of the road is broken, but this sign is posted at the roadside. Which one governs what you may do?

The sign, because it prohibits passing regardless of the marking

A broken line shows where passing is physically possible, and a sign that prohibits passing removes the choice anyway. When a sign and a marking seem to disagree, follow the more restrictive of the two and you will be both legal and safe.