What is this?

This isn't too hard, but I did play with the photo to make it a little harder to figure out.  I'll post a less modified shot later today with an explanation.

Canon EF 50mm f1.4 USM lens
Exposure 1/6 sec @ f22
ISO 100
Curves adjusted for contrast

Lots of good gusses!  This particular day was cloudy, which really helped this shot.  Actually, I took ~20 photos this day and I didn't think many of them would turn out. As it turns out, I think about half of them are shots worth posting and you should see them soon.   

I was in a park that had a creek running through it and a set of commuter train tracks that bounded one side.  The train tracks crossed a bridge over the creek and I was walking under the bridge when a train passed overhead.  I got off 6 shots and I had the presence of mind to flip it to shutter priority mode for the last shot.  I though it was pretty cool.  In this less modified shot, you can clearly see the ties that support the rails.  I thought it was cool that my hand moved during the exposure, but it really didn't mess up the shot. Here's the slightly less processed version.

With 'normal' shutter speed.

Canon EF 50mm f1.4 USM lens

Exposure 1/400 sec @ f4.5

ISO 200

Curves adjusted for contrast