Turning 'the ground below' into public space

ArchDaily’s latest roundup argues that the land under highways, rail viaducts and flyovers is no longer being treated as leftover space, but as public realm that can be designed, programmed and maintained. (archdaily.com) The article, published April 13, 2026, points to projects where the “ground below” has been turned into parks, paths, markets and event space instead of parking lots or fenced-off service land. ArchDaily says the shift depends on design choices such as lighting, planting, circulation and regular programming. (archdaily.com) One of the clearest examples is Toronto’s Bentway, a public space under the Gardiner Expressway that Waterfront Toronto says transformed more than four hectares, or 10 acres, west of Strachan Avenue to Spadina Avenue. The Bentway says the site now hosts year-round events and is still expanding westward and into a second site called Bentway Islands. (waterfrontoronto.ca, thebentway.ca, thebentway.ca) Toronto moved the idea from one project to a corridor-scale plan in April 2024, when City Council endorsed the Under Gardiner Public Realm Plan for spaces from Dufferin Street to the Don Valley Parkway. The Bentway said the plan followed two years of work with the city on a comprehensive vision for underused land below and beside the expressway. (thebentway.ca) Miami is doing the same thing beneath transit. Miami-Dade County says Phase 2 of The Underline opened on April 24, 2024, extending the park by 2.14 miles; the full project is planned as a 10-mile route under Metrorail and is expected to be completed in 2026. (miamidade.gov, theunderline.org) New York has framed the issue as a citywide street-design problem, not just a park project. The New York City Department of Transportation says the city has nearly 700 miles of elevated infrastructure, and it uses the term “El-Space” for the land beneath and beside subways, bridges and highways that can be redesigned for access, safety and connectivity. (designtrust.org, nyc.gov) ArchDaily also cites research showing that these spaces do not improve automatically once a structure is overhead. Its article points to a 2025 study in Shanghai that found centrally located sites with intentional design interventions drew more public use, while peripheral sites remained fragmented and underused. (archdaily.com) The design constraints are physical as much as political. ArchDaily says light, ventilation, noise, heat and safety vary sharply from site to site, and research it cites from Cairo found poor microclimates and limited greenery can keep flyover spaces excluded from daily public life. (archdaily.com) That is why many of the projects in the roundup mix hard infrastructure with constant management. The Bentway combines events with landscape and skating space, while The Underline combines walking and biking routes with art, wellness programming and neighborhood connections along the Metrorail corridor. (thebentway.ca, theunderline.org, miamidade.gov) The common argument is simple: cities built elevated infrastructure to move cars and trains overhead, and are now redesigning the land underneath for people on foot. ArchDaily’s survey suggests the next fight is less about whether those spaces can be public, and more about who funds, programs and maintains them block by block. (archdaily.com, nyc.gov)