Kinzie St. Railroad Bridge (Chicago)
I just returned from a week in Chicago for business. I did manage a turbo walking tour on my last full night in town. Here is the railroad bridge near Kinzie and Canal Streets, built in 1907. It's a tricky shot because I had to stand on a similar steel bridge to shoot it, and said bridge is almost always shaking, sometimes bouncing, from the cars, buses, even pedestrians crossing it continuously. So this was a study in increasing ISO and opening up a bit to mitigate a shorter than optimal shutter speed, then waiting very patiently for a rare lull in the bridge vibration to open the shutter for no more than 2-3 seconds, then close it just as the next car hit the steel bridge.
Luckily, there were several water taxis and other boats passing under to allow this lucky catch.