Wow that's pretty cool. I think it's a great idea. As the strip district gets more infill over the years that would be a nice link to the Northside. Although, the three sisters do a pretty good job of connecting the part people would actually walk between. From the same page, massing idea of a built out strip:
http://aiapgh.org/wp-content/uploads...VisionPlan.jpg
That second drawing is pretty disturbing though; Maracas, train horns & jingle bells hanging alternately from above? What the christ?
EDIT: i see those are just a couple of several drawings that were entered.
And yeah, that track is quite active.