[reaperducer]

The Red Line and Blue Line of the L both run underground.

I once lived in a building that connected to the pedway, so I was able to dress in shorts and a T-shirt in a Chicago winter, navigate underground through the pedway to the Blue Line, then take the Blue Line to O'Hare for a flight to Tampa.

The train part was a bit chilly, but it was better than having to drag a winter coat with me on the plane.