Preview:

The Golden Triangle, the area bounded by the Monongahela, Ohio and Allegheny Rivers and the Crosstown Expressway, has traditionally defined “Downtown.” Early on, participants in this study recognized the North Shore of the Allegheny, the South Shore of the Monongahela and the adjacent areas of the Strip, Hill and Bluff as integral parts of the center city, both now and in the future. The group also agreed that Downtown serves a regional role—as transportation hub, symbol of national and international recognition and identity, and a main stage for business, sports and cultural achievement. Current conditions and future demand were measured in three main areas: economic viability and growth; Downtown’s transportation requirements, now and in the future; and how best to complement Pittsburgh’s natural features and physical form, using design guidelines and other available tools.

See the book here:
http://www.briem.com/files/DowntownSum.pdf