Steep ascend and steep descend

Where you'll see it

On any road but especially in mountainous areas

What it means

To warn that the road will climb or descend steeply

What you must do

Be aware of slow-moving traffic, particularly in mountainous areas with sharp curves. Allow for a longer stopping distance on a descent and especially when your vehicle is heavily laden

Source: Signs manual W322, TW322, W323, TW323