What should you be aware of when you see this sign?

Explanation: Where there's a hidden dip (dead ground), you should be aware that there could be oncoming vehicles out of sight between you and the road in the distance. Don't start to overtake until you can see into the dip and know the road ahead is clear.

Category: Band 2 traffic signs and signals

References: Highway Code: Page 109, Know Your Traffic Signs: Page 13