Well, it looks like the city has another renovation plan its considering. In the Tribune, the Chicago Central Area Action Plan is outlined. Below is the proposed West Loop Transportation Center.
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A four level, $2 billion transporation center under Clinton Street. It would connect Union Station and the Ogilvie Transportation Center served by Metra trains with CTA bus and rail lines, Pace buses, a proposed Carroll Avenue transit line and long-distance Amtrak high-speed trains.
Check out the Tribune article for some of the very interesting proposed changes.