A plan to introduce healthier, more active spaces above downtown’s Connector appears to be not only still alive but moving forward.

An early vision for what could grow into a $400 million development sewing together three-fourths of mile of downtown with green space first emerged back in 2016. The concept is fittingly called “the Stitch.”

That initial design study mapped out pipe-dream plans to cover a half-mile stretch of the Interstate 75/85 Connector with concrete, creating a long tunnel for cars and a 14-acre canvas above for green space, between the Civic Center MARTA station and Piedmont Avenue.

The Stitch idea has been undergoing engineering and feasibility analyses over the past couple of years, and on March 1, an advisory services panel conducted by the Urban Land Institute will share its findings with the public.

Stakeholders can also meet the panel and weigh in on the project February 25 at St. Luke’s Episcopal Church in downtown.

One of the most difficult parts of stitching together a significant span of busy highway—14 lanes wide, in places—is carrying out construction projects without shutting down traffic, A.J. Robinson, Central Atlanta Progress president, told WSB-TV. The project, he said, could potentially be built in phases.

If fully realized, however—and that could take a decade or two—The Stitch could yield between $1.1 to $3.1 billion in value creation, CAP estimates.

According to a statement by CAP officials, that would “generate $21 to $58 million in new revenue, and increase the city’s bonding capacity by $308 to $847 billion by increasing the value of existing properties and catalyzing the redevelopment of underutilized properties.”