Green track

The first green tracks were installed in 1905 along {{ill|Hardenbergstraße|de}} in Berlin.{{cite book | url=https://books.google.com/books?id=s3Or-bHGEK0C&pg=PA26 |title=Jahrbuch Stadterneuerung 2011: Schwerpunkt "Stadterneuerung und Festivalisierung" |isbn=9783798323391 |last1=Altrock |first1=Uwe |last2=Kunze |first2=Ronald |last3=Schmitt |first3=Gisela |last4=Schubert |first4=Dirk |year=2011 |language=de |trans-title=Yearbook Urban Renewal 2011: Focus on "Urban Renewal and Festivalization |quote=Die Gestaltung von Rasengleisen ist dabei keineswegs ein neues Gestaltungselement der Straßenbahnplanung. So wurde 1905 das erste Rasengleis der Welt in der Hardenbergstraße in Berlin eingerichtet. [The design of grass tracks is by no means a new design element in tramway planning. In 1905, for example, the world's first grass track was installed on Hardenbergstrasse in Berlin.] |publisher=Universitätsverlag der TU Berlin |access-date=23 February 2023 }} 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.{{cite web |publisher=Eurailpress, DVV Media Group |title=Grünes Gleis – Stand und Überblick: Ein Beitrag des Grüngleisnetzwerks |trans-title=Green track - status and overview: A contribution of the Green Track Network |language=de |url=http://werkstadtmobilitaet.de/portfolio/artikel-gruenes-gleis.pdf |work=ETR – Eisenbahntechnische Rundschau |date=June 2015 |access-date=23 February 2023 |archive-date=20 May 2023 |archive-url=https://web.archive.org/web/20230520151823/http://werkstadtmobilitaet.de/portfolio/artikel-gruenes-gleis.pdf |url-status=dead }}

Green tracks have a number of positive impacts on the urban environment. Green tracks reduce surface runoff by retaining an estimated 50-70% of precipitation, while remaining stormwater is released more slowly and with fewer pollutants.{{rp|10}}{{cite report |url=http://www.gruengleisnetzwerk.de/images/downloads/wirkung.pdf |publisher=Grüngleis Netzwerk |date=n.d. |title=Wirkung und Funktion Grüner Gleise |lang=de |trans-title=Effect and Function of Green Tracks |access-date=23 February 2023 }} The absorbed water is released through evapotranspiration and provides a cooling effect on the surrounding urban micro-climate. Vegetation, commonly grass or sedum, provides an important surface for the deposit and capture of fine particulate matter.{{rp|10}}{{cite web |title=Green Tram Tracks: The Advantages of Implementing Vegetation Systems in Tram Tracks |url=https://nacto.org/wp-content/uploads/2016/04/3-7_Green-Tram-Tracks-The-Advantages-of-Implementing-Vegetation-Systems-in-Tram-Tracks_2010.pdf |work=Institute for Agricultural and Urban Projects at the Humboldt-University, Berlin |via=National Association of City Transportation Officials |first=Hendrikje |last=Schreiter |date=24 June 2010 |access-date=22 February 2023 }} High-vegetation tracks offer sound reduction under ideal conditions of up to 3 decibels,{{cite journal |url=https://asa.scitation.org/doi/10.1121/1.425739 |doi=10.1121/1.425739 |title=The real sound emission of Rasengleis |year=1999 |last1=Fuerst |first1=P. |journal=The Journal of the Acoustical Society of America |volume=105 |issue=2 |page=948 |bibcode=1999ASAJ..105..948F |access-date=23 February 2023 |url-access=subscription }} and are subjectively perceived as quieter.{{rp|12}}

A light rail project in Sydney, Australia identified green track as requiring 81% less concrete compared to embedded track.{{cite press release |url=https://www.parramattalightrail.nsw.gov.au/first-green-track | title=Parramatta Light Rail lays first green track |website=nsw.gov.au |date=7 February 2022 |access-date=23 February 2023 }}

The cooling effect of the green surfaces, particularly in summer, lowers the temperature of the rails themselves, reducing the risk of buckling.{{rp|9}} The city of Dresden estimates that their total installed capacity of green track has a cooling effect, reducing the temperature by {{cvt|10|C-change}} for {{convert|8.8|e9m3|mi3|abbr=unit}} of air per year.

Green tracks, particularly planted with endemic plant species, have positive impacts on the local biodiversity, such as the use of wildflowers that serve as food sources for wild bees, and providing habitats for insects.

File:Combino trams in Nordhausen - 2015.JPG.]]

There are several different designs for green tracks:{{cite book |isbn=9783962450373 |title=Handbook Track Greening |last1=Kappis |first1=Christel |last2=Schreiter |first2=Hendrikje |date=2016 |publisher=Eurail Press |url=https://www.trackomedia.com/media/pdf/6d/a3/92/978-3-96245-037-3_HB-Track_Greening_Leseprobe.pdf |access-date=8 February 2023 }}{{rp|27–30}}

• Track with high vegetation, or top-of-rail (TOR):{{rp|75}} Grooved rails are placed on concrete sleepers, and the surrounding space is filled with dirt up to the grade of the top of the tracks. This technique provides the best noise abatement{{cite web |work=Pro-Bus-Heepen |url=http://pro-bus-heepen.ibk.me/data/downloads/257243/Buergergutachten-Linie5-PBH-2.pdf |language=de |page=59 |title=Das Bürgergutachten zur Straßenbahn-Linie 5 |trans-title=The Citizens' Assessment of Streetcar Line 5 |access-date=23 February 2023 }} 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, it is more difficult to inspect them. The railway area is more difficult to recognize as a dangerous area, and additional protections need to be taken against stray currents. Track with high vegetation can also be crossed or driven on in exceptional circumstances.

File:12 299 Zwickauer Straße.jpg

File:2206 Amsterdamer Straße, Gürtel.JPG.]]

• Track with low vegetation or foot-of-rail (FOR):{{rp|76}} Concrete sleepers are placed upon longitudinal concrete beams, and the space in between the sleepers is filled with topsoil instead of track ballast, with vegetation only reaching the base of the tracks. This has a reduced sound dampening effect, and the uniform green area is visually interrupted. However, inspection and maintenance of the rails is easier and the fasteners corrode much more slowly, as they are not constantly exposed to moisture from the soil. Switches and sensors can be mounted on the tracks, and there is better control over residual electrical current flowing into the ground. This design also allows for normal flat-bottomed rails, which are typically cheaper and easier to maintain than grooved tramway track.
• Track with mixed-level vegetation:{{rp|77}} This solution incorporates low vegetation between the rails and high vegetation outside. This allows for easier inspection of the rails, but creates a visible trough in the green surface area, where dead leaves and debris can collect.

The ground cover requires a stable track bed construction, where the track geometry will not shift after construction. This is commonly accomplished with ballastless track.{{rp|67}} The addition of soil to track ballast would reduce the friction between the individual ballast stones and make it easier for the track to shift out of place, while making adjustments and corrections more difficult. At the same time, extensions and changes are more involved than with conventional track ballast.

The soil surrounding the tracks is planted with grass or other suitable ground cover plant. In comparison, grass tends to require higher maintenance, such as mowing and irrigation,{{cite report |doi=10.26183/5c05fc021efb3 |url=https://researchdirect.westernsydney.edu.au/islandora/object/uws%3A48951/datastream/PDF/download/citation.pdf |year=2018 |last1=Pfautsch |first1=Sebastian |last2=Howe |first2=Vanessa |title=Green Track for Parramatta Light Rail: A Review |publisher=Western Sydney University |access-date=23 February 2023 }}{{rp|6}} and a soil layer of at least {{convert|15|cm|in|0}}. 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 {{convert|4|-|8|cm|in}}. The space between the tracks can also be filled with grass pavers instead of soil. 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.{{cite web |url=https://www.rtl.de/cms/fuer-wildbienen-bluehstreifen-statt-strassenbahnschotter-6b5f40d8-8734-59b8-8078-1ba25adf42f5.html |title=Für Wildbienen: Blühstreifen statt Straßenbahnschotter |trans-title=For wild bees: Flowering strips instead of tramway ballast |date=6 February 2023 |work=RTL |language=de |access-date=23 February 2023 }}{{cite web |first=Jörn |last=Stachura |url=https://www.braunschweiger-zeitung.de/braunschweig/article232319259/Forscher-entwickeln-neue-Braunschweiger-Wildblumen-Mischung.html |title=Forscher entwickeln neue Braunschweiger Wildblumen-Mischung |trans-title=Researchers Develop New Braunschweig Wildflower-Mix |newspaper=Braunschweiger Zeitung |date=18 May 2021 |access-date=23 February 2023 }}

Green tracks are particularly common in Central Europe; in 2015, Germany had a total of {{cvt|565|km}} of green track.{{rp|16}} In France, the government prescribes the use of green track wherever practicable for tramway construction.{{rp|24}}

File:Parramatta Light Rail Green Track.jpg|Parramatta Light Rail Green Track.

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-vegation tram tracks in Freiburg, Germany

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

{{Portal|Architecture|Ecology|Environment|Trains|Transport}}

• Conservation development
• Environmental design
• Environmental planning
• Green infrastructure
• Sustainable urbanism
• Urban green space
• Urban nature
• Water-sensitive urban design

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{{commons category multi|Grass-covered tram tracks|Sedum-covered tram tracks}}

Category:Fills (earthworks)

Category:Grasslands

Category:Permanent way

Category:Railway track layouts

Category:Tram transport

Category:Lawns