TThe Broad Street subway line, which began operating on Sept. 1, 1928, wasn't extended to stations at Walnut or South streets until 1930. That's when South Broad Concourse opened. Christopher Zearfoss, director of transportation programs in the Mayor's Office of Strategic Planning, says the subway was intended to be "the main artery for a more extensive subway system" that would've connected City Hall with neighborhoods throughout the Philadelphia region. But that never happened. So, though it's become more connected to other forms of transportation via the expansion of Market Street and the Center City Commuter Connection, the concourse remains unfinished and underutilized with regard to its initial intention: to grow.
In years gone by, in basements of office buildings with doors leading to the concourse — the Wanamaker Building, the Philadelphia Bank Building and the Ritz-Carlton building — there have been barber shops and modest retail establishments (specifically newspaper vendors) but nothing beyond that. Today, all those doors leading to the concourse are locked, accessible only to those with special access cards and identification.