Interesting pattern and I've actually noticed something adjacent to this - not Dogman specifically but a lot of the more credible shadow figure reports I've catalogued over the years tend to cluster around disused rail corridors. Old tunnels especially. My working theory is it's got nothing to do with the creature itself and more to do with the environment. Tunnels and cuttings create natural acoustic anomalies, they mess with light in predictable ways, and wildlife like foxes or deer get funnelled along those corridors which could explain misidentification.
That said I'm not willing to fully dismiss the geographic clustering angle. If there's something genuinely anomalous happening it would make sense that it follows human infrastructure rather than avoiding it, which is actually the opposite of what most people assume.
Anyone pulling together actual coordinates on this? Would be useful to map the sightings properly rather than just trading anecdotes. Theres enough Dogman reports floating around now that someone should be doing proper spatial analysis on them.