Inspired by Robert Kosara’s “US ZIPScribble Map“, I wrote my own program to generate this kind of map so I could make a map of Germany’s zip codes. I used the coordinates and zip codes from version 0.2.4d of OpenGeoDB.
Here’s the result (click for larger version):
I computed a TSP (travelling salesman problem) tour of all zip code locations using the Concorde TSP Solver for Windows with a Lin-Kernighan heuristic (which should be quite close to the optimal solution). For the sake of simplicity, I used euclidian distances on the Mercator projection of the map since the Concorde GUI does not support geographic coordinates. The resulting tour has a length of 51799 km:
And here’s a map of area codes, also taken from OpenGeoDB. It looks a lot more random than the zip code map: