New York’s High Line has spawned big public green-space ideas worldwide. Here, the top projects to look for—if they happen at all.

By Stephanie Wu
October 19, 2015
Garden Bridge
A rendering of the proposed Garden Bridge over the Thames.
| Credit: Courtesy of Arup

Garden Bridge, London

The project: A densely planted pedestrian bridge across the Thames by Thomas Heatherwick, between Temple and the South Bank.

The update: Construction won’t begin until 2016, with a projected opening date of 2018.

The verdict: Critics wonder if the city really needs a new bridge—but it has momentum behind it.

The Lowline, New York

The project: A Kickstarter-funded underground park on the Lower East Side.

The update: The team has opened a pop-up Lowline Lab (also Kickstarter-backed) to test out the technology for streaming sunlight underground.

The opening: is slated for 2020. The verdict The transit authority, which controls the space, is on board, but nothing gets built quickly in Manhattan, so it’s anyone’s guess.

Sotto Il Viadotto, Rome

The project: This elevated tramway with workshops and art installations underneath it, 30 minutes outside the city center in Monte Sacro, is part of Renzo Piano’s plan to revive Rome’s suburbs.

The update: Funding is still pending, so the timeline is tentative.

The verdict: Even with the starchitect power behind it, will travelers go to the suburbs?

The Underline, Miami

The project: A 10-mile walkway under the Metrorail, from the Miami River to Dadeland South Station, in a city known for being dangerous for pedestrians and cyclists.

The update: Construction is set to go from next fall to 2022.

The verdict: The city green-lit the project, but the governor is denying funds—expect battles ahead.