Here is an article from a local news website a few weeks ago:
In other words, a tree is busy eating a nearby traffic sign. Apparently the tree views the traffic sign as a sort of “wound” or “injury” which it needs to heal. It does so by growing around it. If you click the article, you’ll see a second photo at the end of the article with how the tree and sign looked back in 2005. It is definitely a slow process, but it makes for some cool pictures!
Life in the Hague 