On a narrow road near Leeuwarden you are driving behind a slow tractor. In the middle of the road there is a freshly painted solid line; there is no sign. Your passenger says: 'A line isn't a sign, so you can just cross it to overtake.' Is he right?
No, the line is itself a traffic sign and so it applies
No, but only because this line has just been painted
Yes, only signs along the road are real traffic signs
Explanation
False — you think only signs count. Lines and other road markings are traffic signs in their own right, just as binding as signs and traffic lights. You may not cross a solid line, not even to overtake. (VekaBest p.57-59 (Hoofdstuk 3 §3.4 Aanwijzingen) — wettelijke basis, RVV art. 62-84)