Green track

The first green tracks were installed in 1905 along in Berlin. Due to the technical challenges they posed, many green tracks were phased out in the following decades, but beginning in the mid-1980s, green tracks have seen a resurgence. ==Impact==

Green tracks have several positive impacts on the urban environment. They reduce surface runoff by retaining an estimated 50-70% of precipitation, while the remaining stormwater is released more slowly and with fewer pollutants. The absorbed water is released through evapotranspiration and provides a cooling effect on the surrounding urban micro-climate. High-vegetation tracks offer sound reduction under ideal conditions of up to 3 decibels, and are subjectively perceived as quieter. The cooling effect of the green surfaces, particularly in summer, lowers the temperature of the rails themselves, reducing the risk of buckling. The city of Dresden estimates that their total installed capacity of green track has a cooling effect, reducing the temperature by for of air per year. Green tracks, particularly those planted with endemic plant species, positively impact local biodiversity by providing food sources for wild bees and habitats for insects. ==Types==

. There are several different designs for green tracks: • Track with high vegetation, or top-of-rail (TOR): and a visually uniform green area, as only the track surfaces are visible. The sides of the tracks are generally protected with cavity filler blocks to prevent direct contact between the rails and the soil, keeping the fasteners clean and preventing or slowing corrosion. The soil must be removed during track renewal operations. Soil moisture leads to corrosion in the track and fasteners, and both must typically be replaced during renewal. Because the fasteners are below the surface, they are more difficult to inspect. The railway area is more difficult to identify as hazardous, and additional protection is needed against stray currents. Track with high vegetation can also be crossed or driven on in exceptional circumstances. . • Track with low vegetation or foot-of-rail (FOR): and a soil layer of at least . ==Prevalence==

Green tracks are particularly common in Central Europe; in 2015, Germany had a total of of green track. In France, the government prescribes the use of green track wherever practicable for tramway construction. ==Gallery==

File:Parramatta Light Rail Green Track.jpg|Parramatta Light Rail green track, Sydney, Australia File:Tramtrain Metro Porto Povoa.jpg|Porto Metro outside the city center File:Straßenbahnlinie5-3.jpg|Example of green tracks in Toulouse. File:T1 line in Toulouse, an outbound train approaches the "Arènes romaines" stop..jpg|An outbound T1 train approaches the "Arènes romaines" stop in Toulouse. File:Auditorium rame Citadis n°1010 (2) par Cramos.JPG|An Alstom Citadis 302 in Dijon, France File:Combino VAG auf Rasengleis.jpg|High-vegetation tram tracks in Freiburg, Germany File:Kayseray32 fotoresim 18.png|Trams in Kayseri, Turkey File:Rasengleis mit Rillenschiene.jpg|Grooved tram tracks in grass File:Zwickau-lawn-track-variation.jpg|Sedum used as ground cover in Zwickau, Germany File:J29 413 Calle Goleta, Gleisverbindung.jpg|The Alicante Tram, combining high-vegetation with flat-bottomed rails. File:Rasengleis-Bau 20160630-Straatsburg.jpg|The rails are covered while the track bed is being filled (Strasbourg tramway) File:Streetcar at Seattle City-County Building (now King County Courthouse), 1918 (22936828611).jpg|Streetcar in Seattle, 1918 File:CAF & KT4 Tram Belgrade.jpg|Trams in Belgrade File:Bonnevoie-Cloche d'Or 2024-08 (102).jpg|A green track tramline in Luxembourg File:Wierzbięcice new Poznan (1).jpg|Green track tramline with Moderus Beta tram in Poznań, Poland File:Canberra Light Rail Green Track Prototype.jpg|Two different types of green tracks being trialled in Canberra ahead of being installed in the city's light rail system ==See also==