It’s not gonna happen, guys. The viaduct is no High Line. Joshua Boulet

When no one in this city can agree on what to do about Bertha, or the tunnel, or cost overruns, there's a certain solace in standing in the shadow of the Alaskan Way Viaduct and staring into a truth we all know: That thing has to come down.

In Kate Martin's living room in south Greenwood, not even that is certain.

On a long wooden table littered with rulers and pencils, Martin and Melissa Beams show off a still-unfinished scale model of a new viaduct in the same downtown spot as the old, crumbling one. They're mulling over the shape of the columns holding a park made of foam board. There's a pencil-drawn street and mismatched Matchbox cars. They arrange little pieces of artificial moss on top to show how plants could drape over the edges of a park elevated above the city. A tiny cardboard human stands below, illustrating the sheer scale of the thing. A toy ambulance acts as a make-believe food truck.

Martin and Beams are part of a group called Park My Viaduct, a campaign so hung up on the viaduct—more precisely, the view of Seattle from atop the viaduct, which Martin says Seattleites are "addicted to"—that the group wants to save the structure or build something similar in its place. According to their vision, the space would be home to an elevated pedestrians-and-bikes-only park, like the High Line in New York or the Promenade plantée in Paris. The group (which also includes Elizabeth Campbell, who ran last year's ill-fated campaign to spend $2 million a year studying the possibility of building a monorail) is now studying various options for the project. Soon, they'll release their favored one—likely what amounts to a new, smaller viaduct—and consider filing a citizen initiative.

"It's a personal-possession kind of feeling for people," Martin says of the view from the viaduct. "That structure has been there for over 60 years, so it's been generation after generation after generation enjoying that view from there. I think it's pretty deep-seated."

Beams remembers driving into Seattle on the viaduct at 4 a.m. when she first moved to the city, looking out in awe at a sparkling skyline. She climbed Mount Rainier in 2006, and the viaduct has a view of the mountain she says she doesn't get anywhere else. "You have a weird direct connection," she says, "almost feeling like you can touch it."

Their fantasy park is clearly an overly nostalgic effort to save a piece of the way the city has always been. The problem: It's too damn late.

The city already has a plan for the waterfront, including green space connecting Pike Place Market to the waterfront near the aquarium. The area between the market and the waterfront will offer views from the same height as the current viaduct, according to the city. Marshall Foster, director of the city's Office of the Waterfront, says the city has spent "tens of millions of dollars" designing that plan and beginning work on the seawall, utilities, and drainage in the area to prepare for it.

"It's not that this isn't a great idea," he says. "It's that it's a very late idea and one that we thought carefully about and decided is not best for the public."

A study commissioned back in 2008 wrote off the idea as too difficult to access for emergency services. An elevated park would be "disconnected from the street and the surrounding city," "pose public safety issues," and be "difficult to access," reads the report from a design firm hired by the city.

"Great parks are not perched like tables in the middle of the air," says Cary Moon, who founded the People's Waterfront Coalition, which advocated for tearing down the viaduct and replacing it with surface-street and transit improvements instead of an underground tunnel. "All of the goals they're trying to accomplish are already accomplished more elegantly and gracefully in the [city's] plan."

Bigger than that, Foster says, the fantastical nostalgia of keeping the viaduct as a park clashes with the city's vision for itself.

"Do we want to reach out and reconnect to that waterfront and the history of the place at the street level," he says, "or do we want to loom above it?"

But Martin's group is undeterred. They're funding their $150,000 feasibility study with help from developer Martin Selig, and, while they're reluctant to try an initiative on this year's ballot, Martin says it's not off the table. Where others might see bigger tunnel-related problems to pay attention to instead, they see opportunity.

"It was missed," Martin says. "It's the perfect time to go take another look at it." recommended

EDITOR'S NOTE: A previous version of this article stated that Kate Martin lives in Fremont. Ms. Martin wrote to demand we clarify that she does not live in Fremont, she lives in "South Greenwood, East Ballard, or PhinneyWood." We're going to let you have "south Greenwood," Kate, but PhinneyWood? No. Another error about how much developer Martin Selig has committed to helping fund the feasibility study has been corrected.