Creepy Shadow Figure Caught at Adrian, Michigan's "Ghost Trestle"

One year ago today, we visited Adrian, Michigan to investigate its "Ghost Trestle," after watching this video by YouTuber RyanCoolVids:

Is that creepy or what?

​When we visited the "Ghost Trestle" last year, we could not debunk the video. But we definitely tried.
We drove underneath the trestle bridge, at various speeds and with/without headlights on, to try and spot the shadow figure... or anything that could have given the illusion of one. We also had a team member walk in the same path, while we filmed from a similar distance that Ryan was in his video. It was clearly a person, and looked nothing like the "shadow figure."

So what could it be?

Is it a ghost? Or possibly something else? Let us know what you think in the comments!