Sukhumvit line

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The Sukhumvit line (Thai: รถไฟฟ้า สายสุขุมวิท) or Light Green line, is an elevated metro rail line of the BTS Skytrain in Bangkok, Thailand. From the central Siam Station, where it connects with the Silom Line, the line runs both northwards along Phaya Thai and Phahon Yothin Roads to Khu Khot in Lam Luk Ka District in Pathum Thani, and eastwards along Rama I, Phloen Chit and Sukhumvit Roads, through Bang Na District to Kheha Station in Samut Prakan. BTS daily ridership (2019) is 740,000 passengers per day.[3]

BTS Sukhumvit line
Bangkok Skytrain 2011.jpg
Two BTS Skytrains heading to both directions.
LocaleBangkok, Samut Prakan Province, and Pathum Thani Province
TypeRapid transit
SystemBTS Skytrain
Depot(s)Mo Chit, Kheha, Khu Khot
Opened5 December 1999
Line length53.58 km (33.29 mi)
Number of tracks2
Track gauge1,435 mm (4 ft 8+12 in) standard gauge
Electrification750 V DC third rail
SignallingBombardier CITYFLO 450 moving block CBTC ATC under ATO GoA 2 (STO), with subsystems of ATP, ATS and CBI[1][2]
Route map

Khu Khot
Yaek Kor Por Aor
Royal Thai Air Force Museum
Bhumibol Adulyadej Hospital
Saphan Mai
Sai Yud
Phahon Yothin 59
Wat Phra Sri Mahathat
11th Infantry Regiment
Bang Bua
Royal Forest Department
Kasetsart University
Sena Nikhom
Phahon Yothin 24
Ha Yaek Lat Phrao
Blue Line to Lak Song
Main depot
Mo Chit
Saphan Khwai
Sena Ruam
Sanam Pao
Si Rat Expressway
Victory Monument
Phaya Thai
ARLbangkok.svg  ARL 
Airport Rail Link to Suvarnabhumi
SRT Eastern Line
to Bangkok │ to Chachoengsao
Silom Line to National Stadium
Silom Line to Bang Wa
Chit Lom
Phloen Chit
Chaloem Maha Nakhon Expressway
Blue Line to Tha Phra (via Bang Sue)
Phrom Phong
Thong Lo
Phra Khanong
Chalong Rat Expressway
On Nut
Bang Chak
Udom Suk
Chaloem Maha Nakhon Expressway
Third stage Expressway System
Bang Na
Pu Chao
Kanchanapisek Expressway
Chang Erawan
Royal Thai Naval Academy
Pak Nam
Phraek Sa
Sai Luat


The first part of the line opened in December 1999 and consisted of seventeen stations from Mo Chit to On Nut. Currently, there are 47 stations in operation for more than 50 km from origin to destination. Its formal name is The Elevated Train in Commemoration of HM the King's 6th Cycle Birthday 1st line (Thai: รถไฟฟ้าเฉลิมพระเกียรติ 6 รอบพระชนมพรรษา สาย 1).[4]


A planned station at N6 has never been built.

Code Station Name Transfers Location
English Thai
  Khu Khot คูคต Lam Luk Ka Pathum Thani
  Yaek Kor Por Aor
(RTGSYaek Kho Po O)
แยกคปอ. Don Mueang Bangkok
  Royal Thai Air Force Museum
(RTGSPhiphithaphan Kong Thap Akat)
พิพิธภัณฑ์กองทัพอากาศ Don Mueang Airport People Mover (Planned)
  Bhumibol Adulyadej Hospital
(RTGSRong Phayaban Phumiphon Adunyadet)
  Saphan Mai สะพานใหม่ Bang Khen
  Sai Yud
(RTGSSai Yut)
  Phahon Yothin 59
(RTGSPhahon Yothin Ha Sip Kao)
พหลโยธิน 59
  Wat Phra Sri Mahathat
(RTGSWat Phra Si Mahathat)
วัดพระศรีมหาธาตุ  MRT  (under construction)
  11th Infantry Regiment
(RTGSKrom Thahan Rap Thi Sip Et)
กรมทหารราบที่ 11
  Bang Bua บางบัว Chatuchak
  Royal Forest Department
(RTGSKrom Pa Mai)
  Kasetsart University
(RTGSMaha Witthayalai Kasetsat)
มหาวิทยาลัยเกษตรศาสตร์  MRT  (design phase)
  Sena Nikhom เสนานิคม
  Ratchayothin รัชโยธิน
  Phahon Yothin 24
(RTGSPhahonyothin Yisip Si)
พหลโยธิน 24  MRT  (proposed)
  Ha Yaek Lat Phrao ห้าแยกลาดพร้าว  MRT  Phahon Yothin
  Mo Chit หมอชิต  MRT  Chatuchak Park
  Saphan Khwai สะพานควาย Phaya Thai
  Sena Ruam เสนาร่วม[5]
  Ari อารีย์
  Sanam Pao สนามเป้า
  Victory Monument
(RTGSAnusawari Chai Samoraphum)
อนุสาวรีย์ชัยสมรภูมิ Ratchathewi
  Phaya Thai พญาไท    ARL   SRT  (planned)
  Ratchathewi ราชเทวี  MRT  (under tender)
สยาม  BTS  Pathum Wan
  Chit Lom ชิดลม
  Phloen Chit เพลินจิต  MRL  (proposed)
  Nana นานา Khlong Toei and
  Asok อโศก  MRT  Sukhumvit
  Phrom Phong พร้อมพงษ์
  Thong Lo ทองหล่อ
  Ekkamai เอกมัย
  Phra Khanong พระโขนง
  On Nut อ่อนนุช
  Bang Chak บางจาก Phra Khanong
  Punnawithi ปุณณวิถี
  Udom Suk อุดมสุข  BTS  Bang Na (proposed) Bang Na
  Bang Na บางนา
  Samrong สำโรง  MRT  (under construction) Mueang Samut Prakan Samut Prakan
  Pu Chao ปู่เจ้า
  Chang Erawan ช้างเอราวัณ
  Royal Thai Naval Academy
(RTGSRongrian Nairuea)
  Pak Nam ปากน้ำ
(RTGSSi Nakharin)
  Phraek Sa
  Sai Luat สายลวด
  Kheha เคหะฯ


BTS operates services throughout the line from Khu Khot to Kheha at all times. At peak hours some services run terminate at Mo Chit northbound, and at Samrong, eastbound. Trains run generally at three to six-minute intervals. The last eastbound trains from Khu Khot terminate at Kheha, Samrong or Ha Yaek Lat Phrao. The last northbound trains from Kheha terminate at Khu Khot, Mo Chit, or Samrong.

A few off-peak eastbound trains run a through service on the Silom Line to Bang Wa, in order to increase the line capacity at peak hours. At night, these trains will run back northbound and head to depot.[6] Some late northbound trains on the Silom line switch to the Sukhumvit line at Siam to reach the depot at Mo Chit.

Extensions and current constructionEdit

Station sign at Thong Lo BTS station shows the extension beyond Samrong which opened in 2018.

Summary of BTS Sukhumvit extensions

  • 12 August 2011: On Nut (E09) – Bearing (E14)
  • 3 April 2017: Bearing (E14) – Samrong (E15)
  • 6 December 2018: Samrong (E15) – Kheha (E23)
  • 9 August 2019: Mo Chit (N8) – Ha Yaek Lat Phrao (N9)
  • 4 December 2019: Ha Yaek Lat Phrao (N9) – Kasetsart University (N13)
  • 5 June 2020: Kasetsart University (N13) – Wat Phra Sri Mahathat (N17)
  • 16 December 2020 Wat Phra Sri Mahathat (N17) – Khu Khot (N24).


1st extension to Bearing Construction started in August 2006 on a four billion baht, 5.25 km extension from On Nut (E9) to Bearing.[7] The extension was funded by the BMA.[8] The original scheduled opening date was mid-2009. However, a delay in tendering of the contract for the electrical and signalling works resulted in a two-year delay.

The extension did not open until over two years later, on 12 August 2011. The delay in opening prompted the BMA to offer free travel for this extension until the end of 2011 as compensation. An additional flat fee is charged additionally to the distance-based fare of the rest of the BTS network.

2nd extension to Kheha Construction started in April 2012 on a 12.6 km, nine station extension from Bearing station to Kheha station. The extension was funded by the MRTA as it is outside BMA city limits, Bangkok Province. Construction was contracted to take 1,350 days and the extension was originally scheduled to open by early 2017. In April 2013, the MRTA awarded Ch Karnchang the contract for track laying and electrical systems.[9]

In June 2014, civil works were stated to be 28.3 percent complete. In August 2016, the BMA agreed to take over the operation of the extension from MRTA. Delays over the agreement of how much the BMA should pay MRTA caused a delay in the commencement of test runs on the extension. Track works were 98% completed by November 2016. The total cost of the extension was estimated at 21.4 billion baht.[10] In January 2017, it was announced that the opening of the extension could be further delayed to 2018-2019 due to budgetary concerns and ongoing disputes between the MRTA and BMA.[11]

The first 1.2 km section of the extension to Samrong station (E15) opened on 3 April 2017.[12] The full extension to Kheha opened on 6 December 2018.[13]


Map of North Extension at Thong Lo station. Station N9 was opened on 9 August 2019 and stations N10 to N24 opened in 2020.

1st and 2nd extension

  • 1) Mo Chit station to Saphan Mai: 11.4 km, 12 stations (N9–N20)
  • 2) Saphan Mai to Khu Khot: 7.5 km, four stations (N21-N24)

An 11.4 km, 11 station northern extension from Mo Chit station to Saphan Mai in Don Mueang District had been planned since the Sukhumvit line opened. Originally, this extension was scheduled to be completed by 2008. However, due to a combination of changes in government, a prolonged environmental study, and problems with locating a suitable train depot the extension was continually delayed. A further 16.5 km, nine station extension from Saphan Mai to Khu Khot was also planned once the extension to Saphan Mai had been completed.

After multiple delays, in mid-2013 a decision was made to tender extensions (1) and (2) at the same time, by the end of 2013. However, the dissolution of parliament in November 2013 delayed this yet again. A tender was finally released in January 2014[14] with an April deadline before being delayed until late May 2014 due to concerns from bidders.[15] A military coup in late-May 2014 suspended the bidding process whilst the military administration reviewed all major projects. In late June, the military administration affirmed that the tender would proceed before the end of 2014. In August 2014, the MRTA announced that the new tender deadline was 30 September 2014.[16] Five bidders qualified and the successful bids were announced in December 2014.[17] The tender specified a construction period of 1,350 days.

On 3 April 2015, MRTA signed four contracts for this extension:[18]

  • Contract 1: Civil works of 11.4 km from Mo Chit to Saphan Mai, will be constructed by Italian-Thai Development (15,269 million baht)
  • Contract 2: Civil works of 7.5 km from Saphan Mai to Khu Khot, will be constructed by UN-SH-CH joint venture (6,657 million baht)
  • Contract 3: Civil works of Depot and Park and Ride building, will be constructed by STEC-AS joint venture (4,019 million baht)
  • Contract 4: Tracklaying and system design, will be constructed by STEC-AS joint venture (2,841 million baht)

The MRTA, contactors and Thai Traffic Police met on 2 September 2015 and confirmed construction would begin on 8 September 2015. A flyover at Kasetsart was demolished, which commenced on 12 September 2015.[19]

At 31 December 2017, the progress of civil works construction was at 53.31% according to the MRTA.[20] As of the end of April 2018, the MRTA stated that civil works progress had advanced to 63.27%.[21] As of 30 September, overall construction had progressed to 78.79%.[22] By the end of March 2019, civil construction had nearly been completed having progressed to 99.42%.[23]

Testing of the final 9.8 km, 7 station section from Wat Phra Sri Mahathat (N17) to Khu Khot (N24) began on 5 October and will continue until the full extension opens.[24] The final section will be officially opened on 16 December 2020 by the Prime Minister.[25]

Opening dates

  1. The first section to Ha Yaek Lat Phrao station (N9) opened on 9 August 2019.
  2. The next 4 stations from a Yaek Lat Phrao station (N9) to Kasetsart University (N13) opened on 4 December 2019.
  3. The next 4 stations from Kasetsart University (N13) to Wat Phra Sri Mahathat (N17) opened on 5 June 2020.
  4. The remaining section of 9.8 km and 7 stations from Wat Phra Sri Mahathat (N17) to Khu Khot (N24) opened on 16 December 2020.

Future extension plansEdit


  • A further 7 km, four station extension from Kheha station to Bang Pu station is planned.
Code Station Name Transfers Location
English Thai
  Sawangkhaniwat สวางคนิวาส Mueang Samut Prakan Samut Prakan
  Mueang Boran เมืองโบราณ
  Si Chan Pradit ศรีจันทร์ประดิษฐ์
  Bang Pu บางปู


  • A further 9 km, four station extension east along Lam Lukka Road from Khu Khot station to Wongwaen-Lam Luk Ka station is planned.
Code Station Name Transfers Location
English Thai
  Wongwaen-Lam Luk Ka วงแหวน-ลำลูกกา Lam Luk Ka Pathum Thani
  Khlong Ha คลองห้า
  Khlong Si คลองสี่
  Khlong Sam คลองสาม

See alsoEdit


  1. ^ "Mass transit signalling". Bombardier Transportation. Archived from the original on 2022-01-01. Retrieved 2020-06-16.
  2. ^ "Bombardier Projects in Mass-transit signalling" (PDF). Archived from the original (PDF) on 2021-11-23.
  3. ^ Limviphuwat, Phuwit (18 May 2019). "Mass Transit not keeping up". The Nation. Retrieved 18 May 2019.
  4. ^ "รถไฟฟ้าบีทีเอส (BTS Skytrain)".
  5. ^ Charuvastra, Teeranai; Chief, News (2019-04-10). "Construction of Sathorn BTS 'Ghost Station' Underway". Khaosod English. Retrieved 2020-03-25. {{cite web}}: |first2= has generic name (help)
  6. ^ "เวลาการให้บริการ". BTS Skytrain.
  7. ^ Groundbreaking starts on new BTS extension, Daily News, 15 August 2006
  8. ^ BTS extension budget cut, Bangkok Post, 15 December 2006
  9. ^ "Ch Karnchang gets Phase 2 of Bearing-Samut Prakan route" The Nation, 13 April 2013
  10. ^ "BMA to postpone test run of Bearing-Samrong skytrain". Bangkok Post. Retrieved 2016-11-22.
  11. ^ Sasiwan Mokkhasen (2017-01-31). "Green Line Going Nowhere for at Least Two Years". Khaosod English. Retrieved 2017-02-25.
  12. ^ Asaree Thaitrakulpanich (2017-02-24). "First Station of Stalled BTS Green Line to Open April 1". Khaosod English. Retrieved 2017-02-25.
  13. ^ "MRTA pushes to fast-track launch of South Green Line". Bangkok Post. 1 December 2017.
  14. ^[bare URL PDF]
  15. ^ "รฟม.ปรับทีโออาร์หมอชิต-คูคต กลางปี59 เปิดให้บริการสายสีม่วง" Prachachat News, 26 May 2014
  16. ^ "ข่าวรอบวัน".
  17. ^ "5กลุ่มบริษัทผ่านคุณสมบัติสร้างรถไฟสีเขียว คาดหาผู้รับเหมาได้ไม่เกินต้นปี58 : มติชนออนไลน์". Archived from the original on 2016-03-04. Retrieved 2014-10-08.
  18. ^ "รฟม.เซ็นสัญญารถไฟฟ้าสายสีเขียวเหนือ เริ่มสร้างมิ.ย 58 คาดเปิดใช้ต้นปี".
  19. ^ "ผู้จัดการออนไลน์ รวดเร็ว สด ทุกเหตุการณ์".
  20. ^ความก-าวหน-าการก-อสร-างรถไฟฟ-า-ณ-31-ธ-นวาคม-2560/. MRTA Press, 16 January 2018
  21. ^ความก-าวหน-าการก-อสร-างรถไฟฟ-า-ณ-30-เมษายน-2561/. MRTA Press, 30 April 2018
  22. ^ "การรถไฟฟ้าขนส่งมวลชนแห่งประเทศไทย on Facebook". Facebook. Archived from the original on 2022-04-30.MRTA Press[user-generated source]
  23. ^ความก-าวหน-าการก-อสร-างรถไฟฟ-า-ณ-30-เมษายน-2561/. MRTA Press, 30 April 2018
  24. ^ "BTS tests Green Line trains at 7 new stations before public opening at year-end". The Nation. 7 October 2020. Archived from the original on 19 August 2013. Retrieved 17 February 2022.
  25. ^ "นับถอยหลัง 4 ธ.ค. 63 รถไฟฟ้า BTS สายสีเขียว เปิดทุกสถานี เชื่อม 3 จังหวัด". TNN Thailand. 17 November 2020.