Never thought about the railroad angle before but now I can't stop thinking about it. Old lines basically carve straight paths through dense woodland for miles and miles, which is exactly the kind of terrain these things supposedly favour, so it tracks.
Yorkshire's got loads of disused rail corridors and I've heard some properly odd stuff from mates who do night fishing near the old Wetherby line. Not Dogman specifically but something moving through the trees at a pace that didn't sound right for anything normal.
Anyone got a map of reported sightings they can overlay against old OS railway maps? That's the kind of correlation that'd actually mean something. Be interesting to see if the hotspots line up.