The ongoing Washington Avenue “road diet” saga must seem particularly confusing to anyone who isn’t intimately familiar with Philadelphia politics.

Yet, thanks to Philadelphia’s vexing commitment to councilmanic prerogative — which gives the final authority on land-use decisions to the city’s 10 district councilmembers — this soap opera, which has dragged on since 2013, is likely to continue.

The inability to deliver a safer street for residents despite nearly a decade of deliberation and outreach is yet another indication that the often counterproductive practice of councilmanic prerogative needs to go.

With five vehicle lanes in some stretches, Washington Avenue is significantly wider than your average Philadelphia thoroughfare. For years, train tracks ran down the middle of the avenue, transporting people and goods back and forth from Center City to the Delaware River ports. When the tracks were paved over during the last half-century, it created wider-than-usual travel lanes: A typical street in South Philadelphia is 30-feet wide; Washington Avenue is nearly 80-feet wide in some parts. Traffic safety experts have increasingly warned that overly wide lanes give too much space to cars and too little to people, which increases the risk of collisions.

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No wonder city officials sought to reimagine the road with pedestrian safety in mind, and last summer, it seemed like they had succeeded. After extensive outreach and a survey that reached thousands of households, the city’s Office of Transportation, Infrastructure, and Sustainability released a supposedly final plan that would reduce most of the 2.5-mile corridor from five traffic lanes to three. The so-called “road diet” redesign plan seemed sure to be adopted — until it wasn’t.

During last week’s City Council meeting, the two members whose districts include Washington Avenue — Mark Squilla, who represents the eastern portion of the street, and Kenyatta Johnson, whose constituents are in the west — were expected to introduce legislation to allow an updated compromise redesign plan to move forward.

Squilla did so, but Johnson did not.

While the City Charter allows any member of Council to introduce such a proposal, the tradition of councilmanic prerogative means Johnson’s support is considered essential for all changes to pass. Johnson used that power to kill the plan, at least for his district’s part of the street.

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That’s a shame. Johnson not only turned the community engagement process into a sham, he rejected a substantive way to slow traffic and improve safety along a once-industrial corridor that is increasingly residential. He has also effectively ignored the wishes of a sizable chunk of his constituency. The collective time and energy from advocates, transportation officials, and ordinary residents who thought they were being given a genuine say in making their neighborhood safer was effectively wasted, all because of one man’s opaque objections.

Johnson’s office insists that the councilmember does, indeed, support increased safety for pedestrians and cyclists, but without the changes in the road’s layout. Instead of a full-fledged redesign, Johnson wants to install new traffic signals, speed bumps, and other measures — steps that pedestrian safety experts have long said are insufficient.

City officials have appealed to Johnson to include his district’s portion of the avenue in an amendment to Squilla’s legislation so the redesign can be implemented. That, however, appears highly unlikely.

Johnson’s inaction creates the real risk of traffic safety inequity settling in on the avenue: Whiter and more affluent sections in the eastern part of Washington Avenue will have more safety measures on those sections of the street than the neighborhoods in the more working-class and predominantly Black western end. That could mean that the historic harms caused by routing heavy vehicle traffic through largely Black residential neighborhoods will continue.

As long as the city’s neighborhoods continue to be run as individual fiefdoms, these bleak outcomes are all but inevitable.