Well, Blackhills has a long history. It's been floating around on these forums for quite a while now. Most of the old issues, for instance the bumpy roads, still exist in this new version of Blackhills. However, some changes have been made. The small town has quite a few more buildings. The roads aren't quite as bad. I'm planning to rework them in Blender after Trynelgren is done. Some jumps have been added. Generally, there is some new stuff.
Just place the downloaded zip in documents/beamng.drive/mods.