Fascinating thread - this absolutely tracks with some of the ley line research I've been doing alongside my Mothman work.
There's a well-documented principle that liminal corridors - boundaries between settled and wild spaces - seem to attract anomalous entity activity. Old railway lines are perfect examples of this. Disused lines especially, where you've got that long narrow strip of disturbed earth, often cutting through woodland that's been isolated from surrounding habitat for 150+ years.
I've run several spirit box sessions near the old Halesowen Railway remnants outside Birmingham and consistently picked up responses that didn't match the ambient environment. Whether that's related or coincidental, I genuinely can't say yet.
What I'd push back on slightly is the assumption that the railway lines are the cause rather than just a correlating factor. My working hypothesis is that these routes were often surveyed and constructed following older paths - drovers' roads, ancient trackways - that already held some kind of significance. The Victorians were pragmatic. They followed the easiest geography, which often meant following routes humans had used for millennia.
Worth cross-referencing any clustering data against:
Pre-enclosure maps, Parish boundary lines, Known folklore accounts from the area pre-1900
Has anyone actually attempted to map the sightings spatially against ordnance survey historical layers? That would be the rigorous next step rather than anecdotal clustering. I'd be genuinely interested in contributing coordinates from the West Midlands region if someone's building a proper dataset.
What regions are people seeing the strongest clustering in?