It is part of one of the two roads linking Stora Svinön to Kräbbleboda, and the one making it possible to go to Hökon. We have a cottage nearby, and have been coming here for +10 years. 

The little loop going south-east, then north again is a track, and sometimes fenced off.

Indeed, most of the roads in the area seems to be classified as tracks, where they are in fact at least tertiary, with signed speed limits of 70 kph