Road transport is the most common form of transportation in nearly every country around the World. Billions of people hit the streets daily to get to work, school and many other places. The convenience of hopping into a car and just driving to your destination without the need of sticking to timetables or the plans of other people makes it immensely popular.
These enclaves/exclaves are located along the border of the European countries of Belgium and Germany, just south of the city of Aachen. Here is an example of what these borders actually mean at some locations: