The coordinate reference system is latitude/longitude and the WGS84 datum.
Comparing this map with the official (but not as detailed) NUTS3 shapefiles from "Statistics Austria" and with Google Maps (all done within QGis) shows differences between the borders of the administrative areas.
Google Maps (and OpenStreetMap, ...) are nearly equivalent with the files from Statistics Austria. Unfortunately, the maps from GADM are not congruent with the other sources. Additionally the distortion grows from West to East.
West of Austria (GADM=red, StatA=green, Google maps as reference):
East of Austria (GADM=red, StatA=green, Google maps as reference):
Of course I tried to import the original data as well as projections to the same CRS (epsg:3857). As expected this did not alter the results.
- Am I using a wrong projection for the GADM data? (Is the documentation on the homepage and the files not corret.)
- How can I get the right projection and get rid of the differences?