(issue) Let’s say Grasshopper has chosen the left route around a mountain, but we want it to chose the right route around the mountain. I suppose we are helpless unless we tinker with OSM’s road data.
Generally speaking the easist way is to use “via” nodes. Please note that this is not possible for your example under https://github.com/graphhopper/graphhopper/issues/1446 because of an access barrier on this node: https://www.openstreetmap.org/node/2271287182.