While a large number of projects are being considered across the country, only a handful are under construction. It can be difficult to get cooperation among city, state and federal authorities, as well as donors, business leaders and developers, Mr. McCabe said.In Atlanta, three plans are under consideration. Each has backing from powerful business groups or executives.

The “Stitch” plan—which preliminary cost estimates put at more than $300 million—would create about 14 acres of new park land, attract businesses and apartment complexes and revive an area “that long lost its luster,” said A.J. Robinson, president of Central Atlanta Progress, the group pushing the Stitch.

“We decided we needed to reconnect what the interstate disconnected,” he said. Early in 2019, the group plans to release a report on the feasibility and cost of creating and
maintaining the park. A team of national experts with the Urban Land Institute is scheduled to visit in February to review the plan and offer advice, according to Central Atlanta Progress officials.