Tokyo's former expressway is becoming a 2-kilometer sky park in Ginza

Tokyo is turning the decommissioned KK Line into a pedestrian-focused green space above Ginza, with public opening phases expected around 2030. The project matters because it could reshape one of the city’s busiest commercial districts while testing a high-profile model for sustainable urban redevelopment.

Why it matters: - The KK Line redevelopment will convert a former elevated expressway into a public park in the middle of Ginza, one of Tokyo’s most valuable commercial districts. - The project could change how Tokyo moves people through dense urban areas by prioritizing walking, greenery and public use over car traffic. - The planned park sits 8.5 meters above street level and stretches 2 kilometers, making it a large elevated public space in a major downtown core. - The project is intended to support Tokyo’s broader push for sustainable, human-centered urban planning.

What happened: - Tokyo is transforming the decommissioned KK Line into a pedestrian-friendly green space known as the Roof Park Project or “Sky Corridor.” - The roadway was shut down in April 2025 after serving Ginza and easing traffic congestion for more than 60 years. - Tokyo Governor Koike Yuriko discussed the project at an April event on the KK Line and called it a “pedestrian-centered public space.” - The Tokyo Expressway Co., Ltd. and the Tokyo Metropolitan Government are leading the regeneration effort. - The project was featured as a partner event for SusHi Tech Tokyo 2026, the metropolitan government’s global innovation conference.

The details: - The former expressway spans the rooftops of 14 two-story commercial buildings. - Those buildings house about 380 tenants, including restaurants, bars, shopping centers, offices and parking lots. - A new underground bypass is planned to absorb the roughly 25,000 vehicles a day that the KK Line carried. - The Tokyo Metropolitan Government says the KK Line will open partially to the public around 2030 and fully sometime between the 2030s and 2040s. - Tokyo Expressway executive managing director Hanaki Mariko said the project is in the stage of technological and social experiments. - Current testing includes measuring asphalt temperatures, studying reuse of materials from the expressway and looking for greening partners. - A Co-Creation Platform of business operators, experts, local governments, communities, citizens and corporations is helping shape the design. - The redevelopment is often compared with New York’s High Line and Paris’ Promenade Plantée, but the KK Line is wider and sits inside a commercial hub. - The project has an official site: Roof Park Project.

Between the lines: - The KK Line is not being treated as a simple park conversion. The plan also includes the spaces underneath the roadway, which suggests a broader district-level remake rather than a single rooftop amenity. - Tokyo is using the site as both an urban planning project and a public test bed for materials, cooling, greening and pedestrian design. - The Ginza location gives the project unusual visibility, but it also raises the stakes because the space sits above active commercial property and close to major landmarks. - The scale and location make the project more of a Tokyo showcase than a neighborhood park.

What's next: - More technical and social testing will continue before the park opens in stages. - Additional design details are expected to emerge through the Co-Creation Platform process. - Public use of the site should expand gradually, with partial opening targeted around 2030. - The broader redevelopment will continue to track the timing of the underground bypass that will replace the former expressway’s traffic function.

The bottom line: - Tokyo is trying to turn a traffic-era relic into a signature public space, and the KK Line will be a high-profile test of whether an elevated road can become a destination rather than a shortcut.