Every overpass on an Interstate;that includes I75. It became the law after several incidents like this, one person was killed and another was severely injured.
The fences have been up for a good ten years.
When I was a kid, I remember reading a story that said:"Local man who loved reading has eyes removed"
Some subhumans had thrown a concrete brick off an overpass and it hit the guys car, smashing his face.
He died a couple of days later.
This has stuck with me all of these years.
My dad said at the time: "Son, I always glance up when I drive under overpasses."
I made it a habit to do that as well.