What must you reckon with when you see these traffic signs?

This traffic sign warns you that the road will narrow ahead, and the distance to this narrowing is approximately 50 meters. The red triangle indicates a danger or warning, and the symbol inside shows two lines coming closer together, symbolizing that the road becomes narrower. The additional plate with "50 m" tells you how far ahead this change will happen.

It is important to prepare for this by adjusting your speed and position on the road, allowing enough space for merging or avoiding obstacles. This sign does not mean the road is narrowing over a length of 50 meters, but that the narrowing will begin after about 50 meters.

In summary, this sign warns of a road narrowing coming up shortly, so you should be alert and ready to adapt your driving accordingly.