Okay this is my idea for a system of transportation in DCA. Bear with me with this. I was thinking of an underground system of those moving walkways at the airport (can't think of the name right now) You could have escalators leading down to them in each land and they would connect with each other. The main hub would be right below Sunshine Plaza. There could even be some kind of show as you move. What escalators have to do with California? I don't know.