What the High Line Teaches About Elevated Park Projects

In 1999 two neighbours in west Manhattan started a group to save a rusting freight viaduct that the city was ready to demolish. Ten years later the first section of the High Line opened, and within a few years it was drawing several million visitors annually to a strip of steel and planting barely 9 metres wide. Almost every city planner I have met since has been asked some version of the same question: can we do one of those?

Elevated park projects look simple from below. Take an old structure, add soil and benches, open it to the public. The reality is a long chain of structural, legal and social decisions, and the High Line is useful precisely because it shows where each of those decisions can go right or wrong.

From Freight Line to Elevated Park

The structure was built in the 1930s to lift freight trains off the streets of the West Side, where street-level rail had caused so many deaths that one stretch earned the nickname Death Avenue. Trucks gradually took over the work, and the last train ran in 1980.

For nearly two decades the line sat unused while property owners lobbied for demolition. Self-seeded grasses and shrubs colonised the track bed. That accidental wilderness became the core of the design argument: the park would keep the feeling of something that had grown on its own.

The key dates

1999: Friends of the High Line forms to oppose demolition
2009: the first section opens to the public
2011: the second section opens
2014: the final section around the rail yards opens
2019: the Spur extension adds a public plaza

The Design Decisions That Made It Work

The design team, led by landscape architects James Corner Field Operations with the architects Diller Scofidio and Renfro and planting designer Piet Oudolf, made three choices worth studying.

First, they kept the rails. Sections of original track were lifted, catalogued and set back into the planting beds, so visitors read the structure's history without a single sign. Second, they used long concrete planks that taper into the planting, blurring the line between path and garden. Third, the planting was chosen for how it looks across all four seasons, not only in summer, so the park still has structure and colour in February.

The result is a path that slows people down. Most visitors walk the full length of roughly 2.3 km at a stroll, and the narrowness that looks like a weakness on paper is part of what makes it feel intimate.

What Elevated Park Projects Actually Cost

Reuse is often sold as the cheap option because the structure already exists. That is only partly true. The first two sections of the High Line cost on the order of 150 million dollars, much of it spent on steel repair, lead paint removal, drainage and waterproofing that no visitor ever sees.

Cost area	Why it is larger than expected
Structural repair	Decades of corrosion and loads never designed for crowds
Drainage and waterproofing	Soil and irrigation add weight and water to an old deck
Access	Lifts and stairs for accessibility at each entrance
Ongoing maintenance	Gardening, security and cleaning every day of the year

That last line is the one most proposals underplay. The High Line is maintained largely by its nonprofit conservancy, which raises most of its annual operating budget privately. A city that copies the build without copying the funding model ends up with a beautiful structure that slowly declines.

Other Elevated Park Projects Worth Comparing

The High Line was not the first. Paris opened the Promenade Plantee, now called the Coulee Verte Rene-Dumont, on a disused railway viaduct in 1993, and it inspired the New York advocates directly. Other cities have since tried their own versions.

Seoullo 7017, Seoul: a former highway overpass near Seoul Station turned into a walkway of planters in 2017. It reconnected neighbourhoods split by rail tracks, but critics found it hard and hot compared with a garden.
The 606, Chicago: the Bloomingdale Trail, opened in 2015, runs about 4.3 km through residential districts and works more as a cycling and commuting route than a tourist walk.
The Coulee Verte, Paris: longer and quieter, used mainly by locals, with shops in the arches below.

The comparison shows that "elevated park" is not one type. It can be a destination, a neighbourhood connector or a transport route, and the brief should decide which before any drawing starts.

Why Copying the High Line Usually Fails

The popular advice to cities with an abandoned rail line or overpass is to turn it into the next High Line. I think that advice does more harm than good.

The High Line succeeds because it sits in one of the densest walking environments on earth, between galleries, offices and housing, with millions of potential visitors within a short walk. Put the same design on a viaduct in a low-density district and you get a quiet path with high maintenance costs. Some proposed copies were dropped after feasibility studies showed exactly that.

The other problem is what happens to the neighbourhood. Property values around the High Line climbed sharply, and many long-standing residents and businesses could not stay. The conservancy itself has since acknowledged that the project did not do enough for nearby public housing communities. Any city proposing an elevated park should plan for housing protection from day one, not as an afterthought. Similar questions come up with office to residential conversions, where the building is only half the story.

Lessons for Smaller Reuse Projects

You do not need a viaduct to borrow the High Line's thinking. The same principles apply to a disused rooftop, a dead-end service lane or the leftover space between apartment blocks.

Start with the existing character instead of erasing it.
Design for slow movement, with places to stop every 30 to 50 metres.
Plan planting for twelve months, not one season.
Secure maintenance funding before construction.
Involve the people who already live nearby, and keep involving them after opening.

We saw the same pattern on a much smaller scale when turning a shared courtyard into something people use: the space worked once neighbours had a reason and a place to linger.

FAQ About Elevated Park Projects

How long does an elevated park project usually take?

From first campaign to full opening, a decade or more is normal. The High Line took about fifteen years from the founding of its advocacy group to the completion of the main sections, with most of the early years spent on legal and ownership questions.

Is it cheaper to reuse an old structure than to demolish it?

Sometimes. Demolition of a long steel structure over streets is expensive too, which helped the reuse case in New York. But repair and long-term maintenance can make reuse the costlier option over thirty years.

Do elevated parks always raise nearby property prices?

In dense, desirable districts they usually do, which is why housing protections matter. In low-demand areas the effect can be small, and the park may struggle to attract regular use.

The Takeaway for Anyone Proposing One

Before sketching planters, answer three questions: who will walk here every week, who will pay for maintenance every year, and what will protect the people already living nearby. If those answers are solid, an elevated park can transform a forgotten structure. If they are vague, the better project may be a smaller one at street level.