The sign you're referring to is the Narrowing Sign, which indicates that the road ahead narrows and there will be oncoming traffic. It often comes with an integrated sign 279, which means there is a right entry point where vehicles can merge or join the traffic from a right side road.

What this sign is essentially communicating to drivers is that the lanes may reduce in number as you proceed, and you must be prepared for oncoming traffic. This can also mean that you need to adjust your speed and driving behavior to accommodate the narrowing of the road.

As you approach this sign, it's important to stay alert for other vehicles, especially those entering the roadway from the right. Always ensure you maintain a safe distance from the vehicle ahead and be ready to yield if necessary.