GREEN
12/07/2011 12:26 pm ET

German Autobahn Park Will Cover 3 Miles Of Freeway, Reunite Hamburg Districts (VIDEO)

Three districts of Hamburg, Germany that have been divided by the A7 autobahn for 30 years are about to be reunited by a $1 billion public park that will cover a three-mile stretch of the freeway.

The 10-foot thick canopy -- capable of sustaining full-grown trees -- will connect Hamburg's Schnelson, Stellingen and Bahrenfeld districts, with some areas of the park stretching across six lanes and as much as 100 feet of car traffic underneath. Construction is set to begin in 2012 and take about four years to complete.

Visual improvement aside, the greenway will also provide a significant reduction in noise pollution for the autobahn-adjacent area, which sees an average of 150,000 cars pass through every day. That number is expected to rise to 165,000 by 2025, according to treehugger.com.

The park construction is part of the European Green Capital program, which each year recognizes a new city for accomplishments in environmental sustainability. The European Commission-run program began in 2008, which Stockholm, Sweden taking that year's award. Hamburg was the European Green Capital 2011 winner.

The longest national roadway in Europe, the more than 500-mile long A7 autobahn bisects Germany between east and west and connects the country with Denmark to the north and Austria to the south.

The project is not the first to convert existing or former transit infrastructure into green space. New York City's High Line is a linear park built atop a former elevated railway on the city's lower west side.

High Line designers looked to the Promenade Plantee in Paris for inspiration. That park also took advantage of abandoned train lines to build green space atop a viaduct and beneath its archways.

Philadelphia also has a similar project in the Reading Viaduct, where project leaders are working to convert the more than century old elevated rail line into a linear park.

WATCH the video below for an aerial view of the project:

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