iirc there was a cycling route "Graz Umrundung" but it was mapped to take a wrong turn and lead into a forest.
As far as I could tell it's based on this:
https://www.graz.at/cms/beitrag/10161935/7776245/Graz_Umrundung_Ost.html

I initially wanted to fix that part as it was shown in cycling apps, but I didn't finish it. The route was there already I just tried to correct it.

Source http://www.graz.at/cms/beitrag/10161935/6255534