We have a whole city built using that logic - the national capital, Canberra!I was wondering that as well, my only answer: The road coming in from the left is the official Elbe cycling-way "R1" and just descended from a bridge over the Mulde river, the cycling-way continues as a fully asphalt-road on the right side all the way through the forest. The road entering on the right was a local road for farming and forest-ranger vehicles. It's a dirt road continuing on the left side into the forest.
Fun fact: About a mile and a half into the forest, the paths cross again, cyling-way continuing left, forest track going further on the right hand side.
I guess it's just an example of German bureaucracy when it comes to building things. The R1 cycling-way has been built sometimes in the 1990's I guess and that dirt road was most likely there much longer, in order to avoid any bureaucracy obstacles they might've went for those crossings.