Now cities around the country, including Chicago, Philadelphia and St. Louis, are working up plans to renovate their aging railroad trestles, tracks and railways for parkland. Cities with little public space are realizing they badly need more parks, and the High Line has taught that renovating an old railway can be the spark that helps improve a neighborhood and attract development.

The High Line’s first and second sections cost $153 million, but have generated an estimated $2 billion in new developments. In the five years since construction started on the High Line, 29 new projects have been built or are under way in the neighborhood, according to the New York City Department of City Planning. More than 2,500 new residential units, 1,000 hotel rooms and over 500,000 square feet of office and art gallery space have gone up.

“Cities recognize parks are good for their economies. They’re no longer a nice thing to have, but a must,” said Will Rogers, president and chief executive of the Trust for Public Land, a national conservation group in San Francisco.

The area around the park, sprinkled with small offices under 200,000 square feet, has become a draw for start-ups and creative companies.

“I think the High Line is a big attraction. It’s created a lot more buzz to the area,” said Matthew Bergey, first vice president at the commercial brokerage firm CB Richard Ellis in New York. “Like with any destination, people will come if it’s cool and has buzz.”

Though plans in many cities have a long way to go before becoming reality, a point in favor of reuse is that it can be cheaper to renovate old rail structures than to tear them down. The Reading Viaduct, an old elevated railway line in Philadelphia, would cost $50 million to demolish versus $36 million to retrofit, according to the Center City District, a business improvement group.

In Chicago, where a 2.65-mile elevated rail line slices through four residential areas, tearing down the line would be prohibitively costly. With 37 bridges and large earthen embankments, the Bloomingdale Trail, as it is now called, snakes east to west across Chicago and is simply too big to go.

“If you’ve driven around Chicago, you’ll have seen it,” said Beth White, director of the Chicago office of the Trust for Public Land, which is helping to build the trail.

As with other, similar rail lines around the country, passenger and freight trains have not operated on the Chicago line in at least 10 years. The only traffic most of these lines see is an occasional runner or bike rider, even though trespassing is usually forbidden.

The impetus for redevelopment has mostly come from neighbors rather than developers, because the vision is so grand and stretches across entire neighborhoods. “It’s hard for private development to be visionary unless it’s a large-scale development where you can create a community,” said Mr. Rogers, a former Chicago developer. “Instead, you’re responding to a small site and not a larger community.”

After years of grass-roots work, the Bloomingdale Trail is moving forward after Rahm Emanuel, who made completing the trail one of his campaign promises, was elected mayor in February. Over the next year, design concepts and engineering work will get under way. The Bloomingdale Trail will allow bikes and dogs, interconnect with new and existing ground-level parks and cost $40 million to $75 million.

In St. Louis, plans are in the works to renovate a 2.1-mile elevated rail trestle and turn it into a park as part of a larger waterfront revitalization project. The Iron Horse Trestle, estimated to cost $50 million, does not have a timeline. Organizers hope to have the first one-mile phase completed in five years.

“You have to be deliberate if you want this to last. It’ll reflect St. Louis and be unique to it,” said Susan Trautman, the executive director of Great Rivers Greenway District, a public group developing the Iron Horse Trestle.

Despite the High Line’s visibility and help in showing donors and residents nationwide what is possible with an abandoned trestle, most cities realize they cannot mimic it. The park runs through Manhattan, the most densely populated area in the country, and attracted large sums of money from celebrities.

“The High Line is not easily replicable in other cities,” said James Corner, principal of James Corner Field Operations, a New York architecture firm that designed the High Line with Diller Scofidio and Renfro. “It’s not just, ‘Build a cool park and they will come.’ It’s, ‘Build a cool park and connect it to a framework.’ ”

Developers are hesitant to rely on these potential parks as they assemble new projects. In October, Mike and Matt Pestronk pounced on a 10-story office tower next to the Philadelphia viaduct when it fell into foreclosure and bought it for $5 million. The brothers, who had been watching the building for years and waiting for its price to drop, bought it because it was a good deal. The developers plan to renovate the vacant office tower for $25 million and turn it into apartments.

This article has been revised to reflect the following correction:

Correction: August 2, 2011

An earlier version of this article did not mention Diller Scofidio and Renfro, designers of the High Line project in Manhattan.

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