Chicago Is So Ridiculously Cold That the Railroad Tracks Need to Be on Fire to Keep the

They do that to keep the switch free. Notice there is a siding off to the left? The switch points have to sit properly otherwise there may be a derailment. That siding probably isn't used much so they defrosted it for a one time use. Our most used switches have gas fired flames under them when it is very cold out, the whole yard looks like it is on fire.