I'm off for my constitutional cycle to the High Street through the woods. I'm observing and, in a very armchair sort of way, studying those things called Paths. I believe this branch of science is called Pathology. Yesterday I noticed another triangle and realised that these are likely and will be caused by folk seeking the easier route. It must be what they had before roundabouts. I'm now settled on a best path and it passes two of these triangles.