"This is it," Scissura said, arguing that burying the Gowanus would salvage a crucial transit corridor, open up major development opportunities and be a boon for the environment. "Nothing would do more for communities, commerce and job creation—we have one opportunity to get it right."

Fixing transit blunders has proven a popular way to spend infrastructure dollars. Portions of Riverside Park were created in the 1930s by decking over train tracks that ran along Manhattan's West Side. After a fully loaded dump truck fell through the elevated West Side Highway near Gansevoort Street in 1973, the city tore that highway down, paving the way for the current street-grade boulevard and the creation of Hudson River Park. And in March Gov. Andrew Cuomo announced plans to demolish the Sheridan Expressway in the Bronx, another traffic-clogged thoroughfare that divides the surrounding neighborhoods while blanketing them with exhaust fumes.

But wiping the Gowanus off the map would be enormously expensive. And with the state and the federal government's inability to allocate resources for even rudimentary fixes on the subways and bridges, replacing one of the city's many ill-placed highways may take a backseat to more pressing matters like expanding mass transit. In other words, some past mistakes may be simply too big to bury.

Not so lonesome highway

The Gowanus has been controversial since it first opened in 1941 as part of the arterial highway system envisioned by car-centric city planner Robert Moses. Despite protests from Sunset Park locals, who pushed for the elevated roadway to run closer to the waterfront, Moses laid the thoroughfare down a bustling Third Avenue commercial corridor. Folks in Red Hook saw their neighborhood slashed in half by several lanes of traffic. Two decades later Bay Ridge homeowners bristled as the Gowanus expanded in their neighborhood, when eminent domain was used to raze houses to make way for the Verrazano-Narrows Bridge.

Things hardly improved from there. By the 1990s the Gowanus was clogged with more than 170,000 vehicles a day, pushing frustrated commuters and truckers to begin searching for shortcuts through local streets. All the automotive wear and tear, in addition to the elevated support structure's exposure to the elements, required constant and costly maintenance. In 1996 Scissura had just taken his first job in government, working for a state senator. He can vividly recall what it was like to traverse the roadway.

"There were potholes, pieces were crumbling," he said. "It was just a disaster."

But one year later, a golden opportunity arose to undo Moses' work. At the time the Federal Highway Administration and the state Department of Transportation were considering a $600 million investment to refurbish and possibly replace some sections of the roadway. Community leaders from Sunset Park and Brooklyn Heights, including Jo Anne Simon, now a state assemblywoman, and Scissura's boss, former state Sen. Vincent Gentile (now a council member), successfully sued the agencies, forcing them to incorporate a tunnel option into their plans.

The benefits, they argued, would be huge: A tunnel would not only push all the traffic below ground, but it would also block motorists from jamming local streets when trying to find a less infuriating route. Better still, ventilation systems could be used to filter exhaust fumes and mute the din of traffic that plagued local neighborhoods. If the elevated portion of the roadway were torn down, Third Avenue could become a tree-lined boulevard able to accommodate denser development along its 3.8-mile stretch, creating housing and jobs and boosting the economy. The portions of the roadway that run in concrete canyons through Bay Ridge could be decked over with green space and help reconnect neighborhoods.

The spoils of their legal victory included $375,000 for consultants to work on the tunnel proposal, leading to a Simon-chaired steering committee and a series of maps for potential subterranean routes.

Despite all that effort, the feds wound up scrapping the entire project, opting instead to help fund ongoing maintenance. But now Scissura and Simon argue that the problems have only worsened—thanks in part to the more than 200,000 vehicles that make the trip every day—and that the time has come to dust off the plans and restart the project.

"Those of us who have chaired the steering committee have recently had some conversations about picking the ball up again," Simon said.

Many state bureaucrats who were wary of the tunneling idea are gone, and boring methods have become more sophisticated and more common. The Trump administration has floated the idea of a $1 trillion infrastructure funding package, and New York's governor has shown a willingness to champion big projects like the Second Avenue subway and the Sheridan Expressway. Plus, taxpayers are already flushing away big money on interim repairs, which have cost more than $350 million since 2005 but will last for only 15 years. Future repairs will become more frequent and more expensive while merely delaying the day when the Gowanus will need to be replaced altogether.

"A tunnel will have a shelf life of 200 years instead of 50," Simon said. "It really is the only environmentally and fiscally sustainable way to go."