These are pictures from underneath a 6 lane interstate overpass, that passes over 18 sets of train tracks and a two lane road, here in Illinois. You can clearly see the concrete support in the background with a vertical crack/separation right through it, top to bottom.
I can't help but think that this is one end result of an Illinois Department of Transportation policy to apply salt or salt brine onto anything that might remotely get slick for 6 months out of the year, from October through April. They will even apply brine to address the threat of frost. And if it rains, they re-apply.
And yes, IDOT has assured the public that this is all safe, that there's nothing to worry about, and nothing to see here... move along please. They'll fix it once it finally gets bad enough, and once they can afford to.
Just remember these pictures as you pass through Illinois, you've been warned.