Noticed this pattern a while back actually. There's old railway lines running through County Antrim and Down that got decommissioned decades ago and the locals have had some properly weird encounter reports along those exact corridors for years. Not just dogman stuff either, general strangeness.
My theory, and its not original, is that old rail lines follow terrain that was already significant before the railways were built. Valleys, ridgelines, old drovers roads. The rail companies weren't stupid, they took the paths of least resistance and those paths often followed routes humans and animals had used for centuries. If theres something living in those liminal stretches of land it would naturally concentrate there.
Also worth noting that abandoned rail corridors are just genuinely isolated now. Overgrown, no lighting, council doesn't maintain them. Good habitat for something that doesn't want to be found.
Anyone cross-referenced the US sightings data with old USGS rail maps? Feels like someone must have done this properly by now. Would be curious what the overlap looks like geographically.