Been following this for a while now and yeah, the clustering along that stretch is hard to ignore. Same thing happened with shadow person reports around the M62 corridor over here about ten years back - dense woodland, lots of underpasses, and suddenly you've got a spike in sightings that just stops being coincidence after a while.
My take is these things follow geographic features more than we give them credit for. Rivers, treelines, that sort of thing. The I-90 runs right alongside some pretty wild terrain in places.
Anyone got the actual dates on the recent reports? Would be good to map them out and see if theres a pattern moving east to west or bunching in one spot. That kind of thing has been useful before when i was looking into the Yorkshire incidents a few years back.