Okay… But Chicago’s subway is famously above ground for a large portion of it. It’s colloquially called “The L” or “The El” which is short for the elevated track. And it’s fine you didn’t know this, but also assuming makes an ass of u and me. I would encourage you to foster an inquisitive and curious mind, not one that assumes (of which I am also very guilty, though working on through meditation and mindfulness.)