"RAPPEL / HERHALING" is a bit strange though. Rappel is French en means Reminder. Herhaling is Dutch and means Repeat. Most likely it's placed under a speed sign.

In the Netherlands there's also such a tree in the middle of the highway. It's along the A27 near Breda. It's probaly the most expensive tree of the country (the road has been designed around the tree and it has a complete drainage system) and known as "de heilige eik" (the holy oak). http...

On highway E4 between Linköping - Södertälje there's an invisible wall right at de gasstation. Also driving over de gasstation / parking doesn't work.