The most memorable for me was not a noteworthy bridge at all, but it's what happened on the bridge that I'll never forget. When I was a kid (probably eight years old or so), my friend and I took a walk along the railroad right next to my house. Back in those days, the track wasn't used very much—usually two trains per day, and at least one of those was at night. We walked farther than usual that day, and came to
this bridge. It was one of those bridge with nothing in between the timbers, just board–gap–board–gap–board. We decided to cross it, what the heck! We got halfway across, to the point where we were directly over the railroad beneath; at that point, a Rock Island Metra train approached from the east on the track below, and blew its whistle just as it reached us. HOLY CRAP!!! I distinctly remember
literally jumping back at least two boards, fortunately not landing in an empty space instead.
We turned around and headed back.