I work with a company that does business with SETPA so have seen blueprints for their tunnels around city hall and MSB and can tell you that the costs to build ANYTHING above the game piece plaza will keep anything from ever being built there. Under that depression/concourse you have the BSL line tracks and the center city commuter rail tunnel underneath that. The BSL follows the 'old' path of Broad St, which as someone posted earlier took a different path around city hall. So from a purely engineering standpoint you would have an extremely complex engineering project here involving building a new structure atop two submerged heavy rail lines... 8 tracks in total plus non-public access tunnels that are there as well.

Aside from that the new Dilworth Plaza idea is interesting... This and the total removal of the family courts/rehab centers complex across from RTM on Market Street/12th would be a blessing in removing a large amount of the riff raff from the area.

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"i live my life in the city"