@third rail posted:On I-55 between Bloomington and Springfield, (I can't remember exactly where) there is an old Illinois Central flat car being used as a bridge over a creek in a farmer's field. On the east side of the highway. I try to see it every time we go to St. Louis. One of these days I will try to get a photo of it.
On the UP line north of Vegas, the UP uses old flat cars as bridges for their vehicle trail alongside The tracks.