Green track

[1] It is a popular way of making railways more visually appealing,[1][2]: 10  particularly for trams and light rail, and providing additional urban green space.

Green tracks reduce surface runoff by retaining an estimated 50-70% of precipitation, while remaining stormwater is released more slowly and with fewer pollutants.

[11]: 9  The city of Dresden estimates that their total installed capacity of green track has a cooling effect, reducing the temperature by 10 °C (18 °F) for 8.8 billion m3 (2.1 cu mi) of air per year.

[10] In particular, shade- and drought-tolerant species are chosen depending on local conditions; sedum is a common choice, as it requires a substrate of only 4–8 centimetres (1.6–3.1 in).

The city of Braunschweig, Germany, together with the Julius Kühn-Institut, developed a mixture of endemic grasses and wildflowers suitable for green tracks that will also provide a habitat for wild bees.

Green tracks with a raised bed, in the Cologne Stadtbahn network.
High-vegetation tracks with cavity filler blocks, Nordhausen .
Low vegetation tracks during construction. The longitudinal concrete beams provide support that otherwise would have come from track ballast.
Low-vegetation tracks with flat-bottomed rails, used by the Cologne Stadtbahn .