Dual carriageway ends

The dual carriageway ends sign warns that the central reservation is about to end, so traffic in both directions will soon share a single carriageway. Finish any overtaking, move back into the left-hand lane in good time and expect oncoming traffic on the other side of the road.

Official Highway Code caption: “Dual carriageway ends.”

Listed under “Mostly triangular” in The Highway Code: traffic signs (GOV.UK). For every sign in more detail, see the Department for Transport’s Know your traffic signs.