Hamburg is Building a Giant Green Roof Cover Over Sections of the A7 Motorway

For decades, the <a href="http://en.wikipedia.org/wiki/A7_motorway_(Netherlands)">A7 motorway</a>, a major north-south highway that connects Germany with Scandinavia, has been a headache for Hamburg residents. The expressway is loud, it creates a physical barrier between neighborhoods, and because it contains heavy truck traffic, it lowers the surrounding air quality. To solve these problems, Hamburg's government arrived at a brilliant solution: <a href="http://hamburggreencapital.eu/urban-development-living/">cover the expressway with a large green roof</a>.

Covering the A7 will reconnect neighborhoods that have been disconnected for the 30 years since the motorway was built.

The A7 is one of the largest and most heavily trafficked expressways in Germany, and it cuts through the west side of Hamburg.

The canopy will be 34 meters wide and 2 to 3 meters thick in places -- thick enough to support mature trees.

Much of the A7 cover will be designated parkland, adding green space to surrounding neighborhoods and helping to keep storm water from entering the city's sewer system.

The designers of the A7 envision large meadows for recreation.

Areas next to the A7 that were previously used for gardening will be developed with housing, and displaced gardeners will be given plots on the new highway cover.