In the early thirties, the ANWB issued three series of large safe traffic stamps with educational images and texts made by the well-known advertising designer Mathieu Güthschmidt. In 1932 the first series of 24 unnumbered stamps of 65 x 45 mm, 12 portrait and 12 landscape, appeared, with the images in sepia and light orange (this set below). This series was soon followed by a series of 18 even larger stamps of 93 x 63 mm in the same colours, on which two images next to each other with the wrong situation on the left and the right situation on the right.
Clearly there are 12 more to find in this series, and a second series to find as well from this artist.
Note that these are not stamps in the philatelic sense of the word. They would more accurately be called "Cinderellas". I normally don't go for Cindies, but these are quite cool looking.