Abstract
The driving along a route to a special destination requires considerable geographical knowledge in the driver. Signalization provides only the main targets along the roads concerned. This is necessary from the point of view of the layout, the size and the legibility of the traffic signs. Therefore the roads are numbered along the roads as well as on maps, so that the itinerary can be planned beforehand. In the Netherlands motorways are numbered with the letter a. Non-motorways have the letter n. Routes in towns sometimes have the letter s. The system of route numbering has proved to be effective. Specifications for the layout of signs with numbers are presented.