Where:
On any dual carriageway or divided road where each direction of traffic is separated by a median, barrier, or central reservation.
These signs are placed in advance of the point where the dual carriageway ends and merges into a single roadway, meaning both directions of traffic will share the same carriageway.

Purpose:
To warn drivers that the one-way, dual carriageway is ending and that vehicles from the opposite direction will soon be sharing the same road.
This alert helps prevent collisions and unsafe lane changes as drivers transition from a separated traffic flow to a two way road.
The sign emphasizes the need for caution, positioning, and awareness of oncoming traffic.

Action:
Prepare to merge into a single carriageway by selecting the correct lane early.
Position your vehicle carefully to avoid endangering oncoming traffic.
Reduce speed if necessary to allow safe merging and to adapt to the new traffic conditions.
Check mirrors and blind spots before changing lanes or adjusting position on the roadway.
Be alert for other vehicles that may also be merging or adjusting their lanes as the dual carriageway ends.
Maintain a safe distance from vehicles ahead and from oncoming traffic to allow sufficient reaction time.
Signal clearly if you need to change lanes or adjust your position on the road to inform other road users of your intentions.