Here’s the one question we haven’t answered in the Market Street arena debate

As the debate continues over the prospect of an arena on East Market Streets between 10th and 11th Streets for the Philadelphia 76ers, it’s time to broaden the discussion beyond two blocks and think about Market Street as a whole.

Market Street is Philadelphia’s Main Street — and has been for over 300 years.

Originally named High Street by William Penn and Thomas Holme in their landmark 1682 plan, Market along with Broad Street anchors historic Philadelphia squarely between the Schuylkill and Delaware Rivers.

East Market Street, stretching roughly a mile and a half from City Hall to the Delaware, was once a vital hub of transportation, commerce, culture, scientific exploration, expression, and education, witnessing Thomas Jefferson’s penning of the Declaration of Independence, Benjamin Franklin’s experiments with electricity, and John Wanamaker’s innovating the modern American department store.

The list of Market Street’s past glory is long and illustrious, including pioneering architecture such as Howe and Lescaze’s PSFS Building (now Loews) and the Wilson Brother’s Reading Terminal headhouse (now the Pennsylvania Convention Center).

A street that once thrummed with energy, which early images depict as an almost colonial mash-up of housing, shops, and crowded market stalls, has evolved into a soulless corridor deadened by nondescript big box architecture, empty lots, and cut-rate stores. And we can’t seem to get it right.

The Parker administration should create a vision for East Market Street.

This is important because we are being asked to approve a proposal to build an 18,500-seat multi-use arena on Market Street for the 76ers. The proposal utilizes a portion of the former Gallery shopping mall, arguing that the central location, atop a vital transit hub and ringed by capacious parking, will be the next golden goose.

As expected, forces both pro and con have lined up to champion and condemn the proposition. An impact study, paid for by the team and conducted by the city and the Philadelphia Industrial Development Corp., was released recently, and its conclusion is mixed.

Gentrification and gridlock in Chinatown are not out of the question. Anticipated tax revenue falls well below the Sixers’ estimation, and while the design review portion of the study deems the arena use appropriate on the selected site, the architects have significant reservations about the scale of the building relative to its position in the street grid and the lack of commensurate public space surrounding it.

Which raises a question: What do we want East Market Street to be, as currently, there is no singular vision for the street.

Just last week, a competing development proposal for the Gallery was put forth by Comcast Spectacor that would turn the upper floors into a biomedical research hub, banking on the surging life-sciences economy in Philadelphia and the site’s proximity to Jefferson.

A 2023 plan by the Center City District envisions East Market as a vibrant mixed-use corridor with housing, shopping, entertainment, and office uses. And there is a 2009 plan by the city that imagines East Market Street as a transit hub and pedestrian-focused, almost European, boulevard connecting with the historic district to the east.

Moreover, the city deemed East Market Street a special signage district in 2012, which brought us large-scale digital advertising along the historic corridor.

How, then, do we decide about building an arena at 10th and Market Streets? By what metrics do we judge the proposal?

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Without a clear, articulated, and approved plan for the street that establishes the character and quality of the public realm along with a vision for how buildings interact with streets and impact adjoining neighborhoods, transit, sidewalks, and pedestrians, we are shooting in the dark. What about public art, for instance?

The Parker administration should create a vision for East Market Street.

Philadelphia is the birthplace of American city planning, and we know that without a vision, there is no clarity. Politics then determine which way the urban planning winds are blowing. A coherent vision should be the result of a transparent public process that gathers the values and feedback from citizens near and far and takes a hard look at the nature of the street today and the kind of street we want it to become.

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How do I know this will work?

From 2006-2007, I led the effort to create a civic vision for the central Delaware riverfront. That vision, borne of anxiety around the advent of casino gaming in Philadelphia, was predicated on citizen values and best planning practices. It wasn’t an easy process. It was long and messy — and often loud. But the vision that resulted is now successfully guiding the development of the waterfront as a human-scaled extension of the city.

Market Street, Philadelphia’s Main Street, deserves nothing less than this kind of attention.

Harris M. Steinberg is the executive director of the Lindy Institute for Urban Innovation at Drexel University.