With the Burial of tracks in certain areas of the city where industry has subsided and/or the tracks are for commuter rails it will free up land for TOD. Here are some examples.
The Greater Rosemont Area.KressonOrangeville25th St.
Madison Square/Johns Hopkins Biotech Park and Berea.And Wabash Avenue/Mondawmin
This post is more pictoral than oral because the pictures tell the whole story.