Traffic does not stop at borders, but the effect of a driving license does, at least technically. For many decades, the underlying principle of territoriality of administrative acts has been overcome by law (first public international law, then European secondary law) requiring states to mutually recognize driving licenses. The evolution of this law reflects a shift in focus from facilitating mutual recognition to harmonising the requirements to obtain a driving license and to preventing “driving license tourism”. This development is in line with the increasing integration of other areas of the internal market, and it shows the importance of common standards (and their observation) as a basis for mutual recognition. Considering mutual recognition a core element of the internal market, it has to be observed that there is still no such “market” for driving licenses.