There is a huge crisis of bridges all over America... I think that's related.
Of course it is infrastructure in general, so some trains are more dangerous then they should be. At first it seems like random derailings or failures that are unrelated to running over people on the tracks are not common, but then it's realized that I have heard of several in my lifetime (just in the single "metro area"), when I should have heard of only from 0 - 3.
The bridges are the biggest issue though because many more people can die. In most of the subway detailings, nobody died. Although a federal evaluation of bridges was done, it was done, many, many bridges were found inadequate in many states, and most states have not put in the funds to actually fix them sense then.
In short, bridges in America are dangerous, so you may wish to avoid them if they look old.