Quadruple-track railway

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A quadruple-track railway (also known as a four-track railway) is a railway line consisting of four parallel tracks with two tracks used in each direction. Quadruple-track railways can handle large amounts of traffic, and so are used on very busy routes or sections. Such conversion is referred to as "quadruplication".

Quadruple track section of the West Coast Main Line, England

A railway line with six parallel tracks, or a sextuple-track railway, has three tracks in each direction. The corresponding term is "sextuplication".

There are also instances of railway lines or sections with eight tracks, and cases with three or five tracks.


  • Quadruple track can carry a larger amount of traffic, with usually at least twice the capacity of double track. It is often seen around large metropolises or on busy inter-city corridors.
  • On quadruple track, faster trains can overtake slower ones, and so quadrupling help speed up trains. High-speed rail with 200 km/h average speed and commuter rail with 40 km/h average can co-exist on quadruple tracks without interrupting each other.
  • Maintenance and engineering work are easier on tracks in quadruple line with little resulting delay because double-track service can continue even if the other two double tracks are halted during the work.


  • Quadruple track costs more, as it requires more materials and increased land acquisition costs. This also applies to tunnelling and bridge costs.
  • When adding tracks, land acquisition can become prohibitively expensive.
  • Maintenance costs are higher and often more complex, as there may be more switches (points) on the track than on a two-track line (to facilitate switching from outer to inner tracks and vice versa).
  • For safety, costly grade separations are almost always required.
  • To provide more capacity, it can be better to add a double track along a different route, because it could improve local and regional transit much along an under-served route[clarification needed], and reduce land acquisition cost by choosing a less built-up area.


In quadruple track, trains are sorted in various ways in order to make maximum use of track capacity. These can include one or a combination of:

  • Sorting by speed

A faster express line and a stopping local line are separated, with each having a separate pair of tracks. Construction of new double tracks dedicated to high-speed rail alongside existing conventional double track used by regional and local passenger trains and freight trains is a form of quadruple track. It increases the capacity of that route significantly, and allows for significant increases in inter-city high-speed train frequency with reduced travel times.

  • Sorting by distance

Long-distance inter-city rail and freight trains are separated from short distance commuter rail. This helps to prevent delays on one service affecting the other, and is commonly seen in metropolitan areas. Quadrupling may be necessary when a new commuter rail service begins to operate on an existing line. Sometimes the local trains have separate technology, such as electrical system or signalling, which requires strict separation, for example in Berlin or Copenhagen.

  • Sorting by destination

When a quadruple-track line divides to different destinations part way along, trains need to be sorted by their destination.

  • Sorting by passenger/ freight

Passenger trains and freight trains can be separated with each different track.

A variation of this can be found on the quadruple track section of the Main Northern line in New South Wales between Waratah and Maitland where one pair of tracks are used exclusively for coal trains and the other pair are used for passenger trains and general freight. A similar process, but with all intercity and commuter passenger trains on the outer tracks and thru-freight trains on the inner tracks, was done by the Pennsylvania Railroad on its New York–Washington and Philadelphia–Pittsburgh mainlines prior to the takeover of operations by Amtrak and Conrail (and later Norfolk Southern). This is somewhat still done to this day by NS, CSX, and Conrail Shared Assets trains on Amtrak-owned trackage in the Philadelphia area.

  • Other modes

Two separate double-track lines in proximity to each other, e.g., two double-track lines along opposite sides of a river, can operate as a quadruple track line. Examples of this can be found in Rhone in France and Rhine in Germany.


As it can be seen from the pictures below in the Gallery of diagrams, the four tracks can be paired either by direction (slow and fast in each pair) or by purpose (speed or direction in each pair). Pairing by direction allows the railway to interface to a double track more easily. With fast trains in centre, local stations can be on the outside, eliminating staircases for half the passengers. With slow trains in centre or when pairing by speed there can be a common platform for local trains with one staircase and one ticket booth.

Sometimes two of the tracks go more straight and with a little distance from the two other. This is a design decision when widening a double track section, and allows higher speed on the faster tracks.




Several lines radiating from Brussels are quadrupled, for instance the Ghent-Ostend line as far as Essene-Lombeek. Further quadrupling has recently been carried out as part of the development of the Brussels Regional Express Network. The building of high-speed lines has also led to quadrupling - for instance the HSL 2 high-speed line between Brussels and Cologne runs inside the local lines as far as Leuven. Meanwhile since 1934 Brussels and Antwerp have been connected by two separate pairs of double track. Fast trains normally use line 25, while line 27 serves slow trains. In places they run parallel, but at times diverge and cross over each other.


There are two places in Denmark with four tracks:

  • Between Klampenborg and Høje Taastrup, through Copenhagen, Denmark, there are four tracks; two are for the separated S-trains and two for mainline trains; where the two tracks closest to Copenhagen (the oldest and central parts of Copenhagen) are reserved for S-trains (on much the lines this is the Northern and Western two tracks).
  • Also between Høje Taastrup and Roskilde, where the two center tracks are for InterCity, long distance commuter trains (further than Roskilde or Ringsted), while the outer two tracks are for commuter trains to/from Ringsted or Holbæk. It has been suggested that the S-trains should continue from Høje Taastrup to Roskilde, but this plan was abandoned; partly due to Roskilde refusing the offer for fear they would become a suburb of Copenhagen, and partly due to construction costs which would exceed the advantages.



By definition German railway lines have one or two tracks. Where more tracks are running parallel to each other, they are considered two or more separate lines. Such routes include:

  • The Berlin Stadtbahn, Germany, has four tracks. Two are for the separated S-Bahn and two for mainline trains.
  • The 112 km long Hamm–Minden railway between Hamm and Minden in Germany is completely quadruple-track with separate tracks for freight and passenger trains.
  • The 50 km long railway from Rastatt to Offenburg in Germany has four tracks.
  • The Hohenzollern Bridge, with six tracks
  • The line from Munich to Augsburg has four tracks and near Munich even more.


Quadrupled section of the Dublin Suburban Rail system


  • The Rome–Naples high-speed railway and the Rome–Sulmona–Pescara railway in Italy combine to form a quadruple track section between Roma Prenestina railway station and Salone railway station.
  • The Milan-Chasso railway and the Milan-Lecco railway run parallel in a quadruple track section from Milan to Monza.
  • The main section of Ferrovie Nord Milano line between Milan and Saronno in Italy. Outer regional trains are segregated from the inner suburban trains.



There are some quadruple-track railways in the Oslo region. They are mostly two double tracks with slightly different routes, one older for local trains, and one newer mostly in tunnels for high-speed and regional trains.



  • All of the mainline railway through Stockholm County (between Järna and Myrbacken north of Märsta, 83 km or 52 mi) has four tracks, sometimes having two routes. There are plans to widen Stockholm–Bålsta and Myrbacken–Uppsala to quadruple track with parts finished or under construction. After this, the Stockholm commuter rail would have its own tracks everywhere. The Swedish Transport Administration is currently planning on extending the quadruple track from a few kilometers north off Upplands Väsby to Uppsala Central Station within the upcoming decade. When having four tracks the local trans go in the middle, which allows a common ticket booth per station.
  • The section between Malmö and Arlöv on the Southern Main Line has four tracks. As of 2018, an extension to Lund is expected to be finished in 2024.[1] It will have local stations on the outside tracks, because manned ticket booths aren't used here.


United KingdomEdit

Quadruple track section of the Midland Main Line, England
  • Significant lengths of the West Coast Main Line, Great Western Main Line, South Wales Main Line, Midland Main Line, South West Main Line, Brighton Main Line, Chatham Main Line, South London line, Windsor Lines between Barnes railway station and Clapham Junction railway station and East Coast Main Line in Great Britain are quadruple track, with the remainder of the lines being double track. These lines are high capacity, intercity rail routes.
  • The Metropolitan Line of the London Underground generally features a four-tracked alignment between Wembley Park and Moor Park. Additionally, from Wembley Park through Finchley Road it shares a four-track alignment with the Jubilee Line, with the Metropolitan Line providing fast (express) service in this section and the Jubilee Line making all local stops. Furthermore, the four-track alignment between the two lines essentially extends from Finchley Road to Baker Street. The two lines run parallel near each other, with the Jubilee Line making two additional stops and the Metropolitan Line running non-stop between the stations.

The AmericasEdit

United StatesEdit

4-track section of Amtrak's Northeast Corridor in New Jersey
East coastEdit
West coastEdit
The four tracks of the Pacific Electric Watts Line in Los Angeles, 1906



Huning Lines

Hong KongEdit




  • The Coastal Railway between Tel Aviv Central and Herzliya. In 2020 construction started on an NIS 5.5 billion (US$1.5 billion in 2018 dollars) project to extend the 4 track section along about 10 km south from Tel Aviv Central to Tel Aviv HaHagana and from there to the Ganot/Shapirim interchange on the Tel Aviv–Lod Railway. In the future, four tracking of the Coastal Railway is also planned to extend north of Herzliya to Haifa in stages.


Four track stretch of the Keihan Main Line in Japan
  • Between Tokyo and Odawara (JR East) 83.9 km is paired by use (not including Shinkansen).[8]
    • Tokyo – Shinagawa 6.8 km: 6 tracks (8 if include Sobu-Yokosuka Line Underground)
    • Shinagawa – Tsurumi 14.9 km: 4 tracks
    • Tsurumi – Yokohama 7.1 km: 6 tracks
    • Yokohama – Totsuka 12.1 km: 4 tracks
    • Totsuka – Ofuna 5.6 km: 6 tracks
    • Ofuna – Odawara 37.4 km: 4 tracks
  • Between Tokyo and Omiya (JR East) is paired by use (not including Shinkansen)[9]
    • Tokyo – Akihabara: 6 tracks
    • Akihabara – Ueno: 6 tracks
      • (Tokyo – Ueno 3.6 km)
    • Ueno – Nippori 2.2 km: 10 tracks (2 for Ueno Depot)
    • Nippori – Tabata: 4 tracks
    • Nippori – Oku: 4 tracks
    • Tabata – Akabane: 4 tracks
    • Oku – Akabane: 2 tracks
      • (Nippori – Akabane 7.4 km)
    • Akabane – Omiya 17.1 km: 6 tracks
  • Between Kusatsu and Nishi-Akashi (JR West) 120.9 km (not including Shinkansen)[10]
    • Kusatsu – Kyoto 22.2 km is paired by direction: 4 tracks
    • Kyoto – Umekoji – Mukomachi 6.4 km is paired by direction: 5 tracks
    • Mukomachi – Ibaraki 21.8 km is paired by direction: 4 tracks
    • Ibaraki – Suita is paired by use: 6 tracks
    • Suita – Shin-Osaka is paired by use: 8 tracks
    • Shin-Osaka – Osaka – Tsukamoto is paired by direction: 6 tracks
      • (Ibaraki – Osaka 14.6 km)
    • Shin-Osaka – Miyahara – Tsukamoto: 2 tracks
    • Tsukamoto – Hyogo is paired by direction: 4 tracks
    • Hyogo – Takatori is paired by direction: 5 tracks
      • (Osaka – Takatori 38.2 km)
    • Takatori – Nishi-Akashi 17.7 km is paired by use: 4 tracks
  • Between Ochanomizu and Mitaka (JR East) 21.5 km is paired by use.[11]
    • Ochanomizu – Yoyogi: 4 tracks
    • Yoyogi – Shinjuku: 8 tracks
    • Shinjuku – Mitaka: 4 tracks
  • Between Kinshicho and Chiba (JR East) 34.4 km is paired by use.[12]
    • Kinshicho – Nishi-Chiba: 4 tracks
    • Nishi-Chiba – Chiba: 6 tracks
  • Between Ayase and Toride (JR East) 29.7 km: 4 tracks/paired by use[13]
  • Between Osaki and Komagome (JR East) about 20 km is paired by use.[14] (see Yamanote line)
    • Osaki – Yoyogi: 4 tracks
    • Yoyogi – Shinjuku: 8 tracks
    • Shinjuku – Komagome: 4 tracks
  • Between Souen and Heiwa (JR Hokkaido) about 9 km[15]
    • Souen – Sapporo is paired by use: 3 tracks
    • Sapporo – Heiwa is paired by direction: 4 tracks
  • Between Niigata and Kami-Nuttari (JR East) 1.9 km: 4 tracks/paired by direction[16]
  • Between Imamiya and Tennoji (JR West) 2.2 km: 4 tracks/paired by direction[16]
  • Between Inazawa and Nagoya (JR Central) 11.1 km/paired by use: 4 tracks[17]
  • Between Hiroshima and Kaitaichi (JR West) 6.4 km: 4 tracks/paired by direction[18]
  • Between Orio and Moji (JR Kyushu) 24.6 km[19]
    • Orio – Kokura: 4 tracks/paired by use
    • Kokura – Higashi-Kokura 1.6 km/paired by direction: 6 tracks
    • Higashi-Kokura – Moji is paired by direction: 4 tracks
  • Besides JR companies, the following private railway companies in Japan run their own quadruple (or more) tracked sections:


The country never implemented a quadruple-track line throughout its history, but there are plans for sections of the North–South Commuter Railway (NSCR) to be quadruplicated.

  • The NSCR will run alongside the Metro Manila Subway between FTI and Bicutan stations from ARCA Road to Mañalac Avenue. Length is 2,628 m (8,622 ft).[20]
  • A branch line to Clark International Airport will have a flyover interchange with the mainline, creating a 1,520 m (4,990 ft) quadruplicated section.[21]
    • A spur to the Mabalacat depot will diverge from the main branch, the latter heading underground. Length is 1,000 m (3,300 ft).[21]

South KoreaEdit





See alsoEdit


  1. ^ "Lund–Arlöv, fyra spår" (in Swedish). Swedish Transport Administration. Retrieved 19 August 2018.
  2. ^ "New York Central and Hudson River Railroad". www.history-map.com.
  3. ^ "New York Central Mileage Chart 1936" (PDF). multimodalways.org.
  4. ^ "Penn Central Transportation Company Track Chart 1975" (PDF). multimodalways.org.
  5. ^ Gideon, Arthur (14 April 2019). "Senin, Perjalanan KRL Masih Terganggu Pengoperasian Jalur Dwiganda". liputan6.com (in Indonesian). Retrieved 21 January 2022.
  6. ^ Japan Railfan Magazine (Koyusha) No. 478 p. 36
  7. ^ Japan Railfan Magazine (Koyusha) No. 478 p. 37
  8. ^ Japan Railfan Magazine (Koyusha) No. 478 p. 10
  9. ^ Japan Railfan Magazine (Koyusha) No. 478 p. 14
  10. ^ Japan Railfan Magazine (Koyusha) No. 478 p. 16
  11. ^ Japan Railfan Magazine (Koyusha) No. 478 p. 20
  12. ^ Japan Railfan Magazine (Koyusha) No. 478 p. 22
  13. ^ Japan Railfan Magazine (Koyusha) No. 478 p. 23
  14. ^ Japan Railfan Magazine (Koyusha) No. 478 p. 24
  15. ^ Japan Railfan Magazine (Koyusha) No. 478 p. 25
  16. ^ a b Japan Railfan Magazine (Koyusha) No. 478 p. 26
  17. ^ Japan Railfan Magazine (Koyusha) No. 478 p. 27
  18. ^ Japan Railfan Magazine (Koyusha) No. 478 p. 28
  19. ^ Japan Railfan Magazine (Koyusha) No. 478 p. 29
  20. ^ "Sec. A2". Basic Design. The Detailed Design Study (including Supplementary Feasibility Study) of the South Commuter Railway Project Package CP S-03b (Report). Vol. II. Japan International Cooperation Agency, Tokyo Metro, et al. 2021-03-24.
  21. ^ a b "Sec. 6". MCRP Detailed Design. The Detailed Design Study (including Supplementary Feasibility Study) of the Malolos Clark Railway Project Package CP N-04 (Report). Vol. II. Japan International Cooperation Agency, Tokyo Metro, et al. 2019-05-06.