Where:
On any road, particularly in areas with temporary traffic management such as roadworks, construction zones, or accident sites.

Purpose:
To warn drivers that traffic ahead is being temporarily controlled using a "Stop / Ry-Go" sign, often managed by traffic controllers or flag persons.
This sign indicates that vehicles may need to stop and wait for permission to proceed in a controlled alternating flow, especially where only one lane is available or roadworks restrict normal traffic movement.

Action:
Reduce your speed and prepare to stop safely.
Observe the traffic controllers signals or the Stop/Ry-Go sign instructions.
Stop completely when the sign or traffic controller indicates, and only proceed when it is safe to do so.
Keep a safe distance from the vehicle in front of you, as stopping may be sudden or at irregular intervals.
Be alert for pedestrians, workers, or machinery in the controlled area.
Follow any additional temporary signs or instructions indicating lane closures, detours, or merging traffic.