For decades, the A7 motorway, 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: cover the expressway with a large green roof.
Spanning six to eight lanes of traffic that cut through the Schnelsen, Stellingen and Bahrenfeld districts of Hamburg, the A7 is among the largest and most disruptive highways in Germany. The current plan calls for installing a 34-meter-wide and 2- to 3-meter-thick canopy over the A7 motorway in three sections, covering a total of 3.5 kilometers.
The A7 cover in Hamburg won’t be the first roadway to be covered in Germany; other canopies can be found in Düsseldorf and Munich, but the A7 cover in Hamburg will be the largest in Germany. The first of the three sections to be built will be the Stellingen section, which will include 893 meters of wooded parkland and garden plots for Hamburg residents. Future sections will include meadows, pathways and more garden allotments.
The A7 cover is expected to cost €600 – €700 million, and it will mostly be financed by the federal government, but some of the funding will also come from selling city-owned land adjacent to the autobahn that is currently being used by gardeners to private real estate developers. The gardeners who are displaced from their plots will be given new plots on top of the green roof canopy. Construction on the A7 cover is set to begin in 2012.