Hey there, while I formulated the title rather general, I do have a specific question. I recently tried to make sense of the track charts for Clinchfield available here. I have taken the following picture from that document: My question is: What do the curved lines alongside the track elevation mean? Since some of these lines correspond to bridges (see picture), I guess that the lines may refer to the elevation of the terrain instead of the track, but if that is the case, then how can the line dip lower than the track elevation without a bridge which happens quite a bit? Can anyone help me out here? Cheers
Surrounding terrain: mountains and ravines. The dips correspond to bridges because bridges go over ravines.