Purple Line (Bangkok)

Route alignment

The Purple line starts from Khlong Bang Phai station in Bang Bua Thong District. The line travels south along Kanchanaphisek Road before turning eastward near Central WestGate, onto Rattanathibet Road. It continues along Rattanathibet Road, passing through a large residential area in Bang Yai District and crosses the Chao Phraya River on a bridge parallel to the Phra Nang Klao Bridge and runs towards Nonthaburi Civic Center station. The line then turns southward onto Tiwanon Road, passing the Ministry of Public Health and turns southeast onto Krung Thep-Nonthaburi Road, entering Yaek Tiwanon station. The line then enters Bangkok city limits at Bang Sue district and passes Bang Son station before terminating at the upper platforms of Tao Poon station, with a total length of 23 km, serving 16 stations.

History

Officially named the Chalong Ratchadham Line () – "To Celebrate the Great King's Reign with Righteousness" – but informally known as the "Purple Line", the rapid transit line provides a north–western corridor in Bangkok's Mass Rapid Transit Master Plan. The line also incorporated an extension of the Blue Line from nearby Bang Sue station to Tao Poon Station.

In the 1990s, the plan for the Purple Line was to run from Bang Phut to Bang Sue for 12 km, with an extension to Thewet for 6.7 km.

This line was created from the adjustment of the 1994 mass transit rail system master plan, which connected the original extension of the Blue Line from Tao Poon to Bang Yai, while the original Purple Line would have run from the National Library to Tao Poon and the original Orange Line from Samsen (National Library) to Rat Burana, becoming a new line designated as the Purple Line, included in the master plan of the Office of Transport and Traffic Policy and Planning (OTP) for the first time in 2004. Five years later, the line's construction began.

Northern section

Construction was divided into six contracts, three of them for civil works. The contracts were signed from late 2009 to early 2010 and completion was originally scheduled for the end of 2014. The third contract included construction of four park and ride buildings at the Khlong Bang Phai, Sam Yaek Bang Yai, Bang Rak Noi Tha It, and Yaek Nonthaburi 1 stations. On 31 March 2017, the fifth contract was effectively terminated and became part of a new Blue Line concession agreement.

The 2011 Thailand floods delayed the construction of the line for nearly one year. In June 2013, five people were injured when six beams fell onto vehicles below Tao Poon station. In July 2014, the civil work was 94 percent complete; in October 2014, civil work was stated to be 99% complete.

The line opened on 6 August 2016, when King Bhumibol Adulyadej appointed Princess Maha Chakri Sirindhorn to represent him in presiding over the opening ceremony and officially pressing the button to open the electric train system. However, the MRT Blue Line extension to Tao poon was delayed, so when it opened the Purple Line could not interchange with the Blue Line as planned. This resulted in low line usage. Even with a reduced fare, the line only attracted about 22,000 passengers daily compared to a goal of 100,000. A shuttle bus service was in operation between Tao Poon MRT station and Bang Sue MRT station to connect with the Blue Line. When the Blue Line extension finally opened a year later, on 11 August 2017, ridership significantly increased. In 2019, daily ridership was 70,000.

Construction contracts

Southern section

As the northern section of the Purple line was built first, the second phase of the Purple Line south from Tao Poon via Rattanakosin – Bangkok's old town to Rat Burana would fully complete the line. The length of the southern extension is 23.63 km: 14.29 km underground, 9.34 km elevated with 17 stations, ten underground and seven elevated. The initial cost of the southern extension is 82 billion baht and with a planned opening by the end of 2027.

The Thai Cabinet was expected to approve the tender in mid 2017 with a tender then to be issued in the second half of 2017. On 25 July 2017, Cabinet approval was given, but the tender was then delayed until 2018. By December 2018, a tender had still not been issued and was further delayed. In August 2019, subject to final land acquisition, a March 2020 tender was planned. In mid 2020, the Ministry of Transport still aimed for a tendering process within 2020 despite COVID-19 related delays. The MRTA then expected to issue a tender in February 2021. and if construction had begun in 2021, the extension was projected to enter service sometime in 2027. However, the tender was delayed yet again and subsequently cancelled in August 2021 until it was finally issued in November 2021.

Construction contracts were signed on 11 March 2022 with a construction period of 2005 days for a planned 2027 opening date.

Construction progress

Contactors were issued with a Notice to Proceed on 25 April 2022 giving them access to sites along the route with actual construction planned to begin from August 2022. Construction began in early August for two contract sections, 3 & 4. Some 410 lots and 500 buildings will need to be appropriated to build the extension and as of May 2022 many of them were still to be surveyed.

Construction progress was at 3.45% complete at the end of September 2022. By the end of November 2022, construction progress was at 4.30%. At the end of February 2023, construction had progressed to 7.73%.

By the end of May 2023, construction had progressed to 11.50%.

As of December 2024, construction has progressed to 46.3% completion.

As of June 2025, construction has progressed to 57.6% completion with an expected opening date of 2028.

In August 2025, it was reported that only the section between Parliament House station and National Library station will open in 2027. The opening date for the whole extension is delayed to 2030.

Sinkhole incident

On 24 September 2025, at approximately 07:13 local time, a sinkhole measuring about 20 metres in depth opened on a section of Samsen Road in Bangkok. The incident occurred near the construction site of Vajira Hospital Station, part of the southern section of the MRT Purple Line.

Following the collapse, the MRTA suspended construction activities at the affected site to investigate the cause of the incident.

Construction contracts

Stations

Under construction

Infrastructure

Depot

The Khlong Bang Phai Depot serves as the main maintenance facility for the entire MRT Purple Line. It is on Kanchanaphisek Road, near Khlong Bang Phai Station. Additionally, the Kru Nai stabling yard is currently under construction as part of the Purple Line Southern Section project. It is near the southern section of Kanchanaphisek Road in Phra Pradaeng District, Samut Prakan Province.

Park & Ride

There are currently four Park & Ride facilities along the MRT Purple Line, at Khlong Bang Phai, Sam Yaek Bang Yai, Bang Rak Noi Tha It, and Yaek Nonthaburi 1 stations. Two additional facilities are under construction at Bang Pakok and Rat Burana stations as part of the Purple Line Southern Section project.

Station

The MRT Purple Line comprises 33 stations, with 16 currently in operation since 2016—all of which are elevated. The remaining 17 stations are under construction and expected to be completed by 2029, consisting of 10 underground and 7 elevated stations.

Station structures on the MRT Purple Line North Section range from 300 to 400 meters in length and approximately 18 meters in width. In the Southern Section, underground stations typically measure 250 meters in length and 20 meters in width, while elevated stations are 153 meters long and 25 meters wide. All stations are designed to accommodate a maximum of six cars per train. Elevated stations are equipped with half-height platform screen doors, while underground stations will be fitted with full-height platform screen doors. In addition, the entrances to the stations are designed to be about one meter above ground level, taking into account the highest recorded flood levels in Bangkok to prepare for potential future flooding events.

Rolling stock

In November 2013, BEM contracted with Marubeni Corp, Toshiba Corp, and East Japan Railway Company to install E&S systems, supply 21 three-car trains (total of 63 cars) rolling stock, and provide maintenance for 10 years as part of a contract worth 12.6 billion baht. East Japan Railway train manufacturing subsidiary J-TREC built them in Yokohama with the first sets delivered in early 2016. The trains are owned by the MRTA which paid for the rolling stock at BEMs request. The southern extension will acquire 17 additional trains, along with the current ones, to create a total of 38 trains.

In total, line is service by 21 three-car trains. Trains are powered by 750 V DC via third rail system, are air-conditioned and capable of traveling at up to 80 km/h. File:MRT Purple Line Train T013 20160806.jpg|MRT Purple Line train entering a station. File:MRT purple line from Central Westgate parking building - panoramio.jpg|Purple Line train spotted near Central WestGate. File:201701 Interior of MRT Purple Line rolling stock.jpg|Interior of a train. File:MRT Purple Line seating.jpg|Interior of a train. File:MRT Purple Line status map.jpg|Dynamic route map File:MRT Purple Line Bangplhu Station (1).jpg|Platform Level at Bang Phlu station

Signaling system

Bombardier Cityflo 650 signaling system has been implemented for the MRT Purple Line project. This communication-based train control (CBTC) system supports automatic train operation (ATO), allowing for efficient and safe control of train movements. It enables real-time train monitoring, optimizing operations and minimizing delays while prioritizing passenger safety. Additionally, the system ensures a minimum headway of just ninety seconds.

Operation

Service hour

The line operates with varying schedules across stations. The first train departs from Khlong Bang Phai station at 5:30 AM and from Tao Poon station at 6:00 AM. The frequency of train services depends on the time of day and passenger volume. The service hours are determined by the departure time of the last train heading to Khlong Bang Phai station. For example, when the last train departs from Tao Poon station at 11:24 PM, that marks the closing time for all stations, with the final closure occurring at Talad Bang Yai Station.

Headways

Ridership

When the Purple Line first opened daily ridership was only 22,000 compared to projected numbers of 100,000. After the opening of the Blue Line extension to Tao Poon 1 year later in August 2017, daily average ridership increased significantly from 33,000 to 50,000.

In August 2018, the MRTA Deputy Governor stated that daily ridership had increased to 60,000 each weekday. By late 2019, this had increased to 70,000. In 2023 the purple line saw an average of 50385 passengers per day.

On 16 October 2023, MRT Purple Line began using the new fare rates of 14 to 20 baht (down from 16 to 42 baht) after the '20 Baht Transit Max Fares Policy' was approved by the Thai government.

From 25 January to 31 January 2025, Prime Minister Paetongtarn Shinawatra implemented a policy of free public transportation in Bangkok for one week. This measure aimed to address the worsening air pollution caused by surging dust levels across all districts of the capital.

Fares

MRT Purple Line fare is calculated based on the travel distance between the origin and destination stations. Previously, fares ranged from 14 to 42 baht, with a maximum of 70 baht when transferring to the MRT Blue Line.

Implementation of the 20-Baht Fare Cap (2023–2025)

Following the introduction of the policy in October 2023, fares were reduced to a range of 14 to 20 baht, with a new maximum of 51 baht when transferring to the Blue Line. Discounted fares were available for children under 14 and senior citizens, starting at 7 baht and capped at 36 baht with a Blue Line transfer. Student fares started at 13 baht and rise to 48 baht when including a transfer to the Blue Line.

The policy was discontinued on 30 November 2025 and was replaced by a 40-baht daily fare cap for credit or debit card users; this policy also applies to the SRT Red Lines.

EMV Payment and Transfer Privileges

EMV Card users will receive a 15 baht discount when transferring from the Purple Line to the Pink Line, and a 14 baht discount when transferring in the opposite direction. Senior citizens are eligible for an 8 baht discount when transferring from the Purple Line to the Pink Line, and a 7 baht discount when transferring from the Pink Line to the Purple Line. Students will receive a 15 baht discount when transferring from the Purple Line to the Pink Line, and a 13 baht discount when transferring from the Pink Line to the Purple Line.

Following the Cabinet's approval on 25 November 2025, a new 'Daily Fare Cap' measure was introduced to reduce the cost of living, effective from 1 December 2025 to 30 November 2026. This policy applies to travel on the MRT Purple Line and SRT Red Lines. General passengers using EMV Contactless cards are subject to a maximum fare of 40 baht per day. Students are eligible for a 10% discount on fares with a daily cap of 30 baht, provided the same card is used for all trips. Meanwhile, state welfare cardholders, persons with disabilities, senior citizens, and children continue to receive their existing discounts or fare exemptions; specifically, senior citizens remain entitled to a 50% discount.

Incidents

2025 Myanmar earthquake

On 28 March, a 7.7-magnitude earthquake in Myanmar struck Bangkok, leading to the temporary suspension of all train services to ensure readiness for resumption and to prepare for potential aftershocks. The line resumed normal service on the next day.

2025 Bangkok road collapse

Main article: 2025 Bangkok road collapse

On 24 September 2025, a section of Samsen Road collapsed, creating a large sinkhole in front of Vajira Hospital. The hole was estimated to be about 30 metres wide and nearly 50 metres deep, swallowing several vehicles and damaging water pipes, power lines, and other infrastructure. Although no injuries were reported, parts of the Sam Sen police station and nearby buildings were evacuated, and the hospital suspended some services for two days as a precaution.

Officials linked the collapse to soil erosion associated with the construction of the MRT Purple Line South section and a possible leakage from water pipes beneath the road. Initial repair work involved pouring large amounts of concrete into the cavity, but engineers were forced to stop when the material began seeping into a nearby tunnel through a breach in its wall. By the following day, the ground continued to shift, complicating stabilization efforts. Authorities responded by closing off the area, installing monitoring equipment, and preparing plans for a permanent retaining wall.

The Bangkok Metropolitan Administration stated that full repairs would require thousands of tonnes of concrete and additional engineering measures. Inspections of surrounding structures are ongoing, and traffic on Samsen Road is expected to resume by 9 October 2025.

Route map

Network map

References

References

1. "Bombardier Projects in Mass-transit signalling".
2. "Purple Line: Newly launched, but few using it". Bangkok Post.
3. Mokkhasen, Sasiwan. (10 May 2016). "Sign up to test ride new MRT Purple Line". Khaosod English.
4. https://www.khaosod.co.th/economics/news_2933591. ''Khaosod'' ,30 September 2019
5. "MRTA to issue measure to reduce fares to attract passengers".
6. "MRTA Purple Line project".
7. (2024-04-07). "Purple Line link 53% completed".
8. "BEM บริษัททางด่วนและรถไฟฟ้ากรุงเทพจำกัด (มหาชน)".
9. "Urban Railway Projects In Bangkok - Measures for Securing Financial Resources".
10. (2009-08-26). "ลงนามสัญญาที่1 รถไฟสีม่วง ช.การช่างได้เฮ".
11. (2010-01-20). "รฟม.ลงนามสัญญา 2 สายสีม่วง มูลค่า 1.31 หมื่นล้านแล้ว".
12. (23 June 2009). "รฟม.ตัดเค้กสัญญา 3 รถไฟฟ้าสายสีม่วง "อิตาเลียนไทย" ได้ทานแห้ว".
13. "รถไฟฟ้าสายสีม่วงบางซื่อ-บางใหญ่ฉลุยเซ็นรับเหมาครบ3สัญญา ลงมือก่อสร้างก.พ.นี้ 3 ปีครึ่งเสร็จ !!".
14. (28 March 2017). "ปิดดีลเดินรถสีน้ำเงิน ครม.ผ่านฉลุย เร่งเซ็นสัญญาจ้าง Bem ทยอยเปิดเดินรถปลายปี 62".
15. "BEM significant event in 2017".
16. (7 June 2013). "MRTA Purple line accident injures 5". Bangkok Post.
17. "คมนาคมตามความคืบหน้ารถไฟฟ้า 10 สาย เร่งสีม่วงเปิดปลายปี'58 ชงคสช.อนุมัติอีก 6 สาย : ประชาชาติธุรกิจออนไลน์".
18. "ระบบรถไฟฟ้าในกทม.และปริมณฑล".
19. "หนังสือพิมพ์บ้านเมือง » คมนาคม เผยความคืบหน้ารถไฟฟ้า".
20. [http://www.prachachat.net/news_detail.php?newsid=1462201042 พิธีเปิดการเดินรถ และกดปุ่มเปิดระบบรถไฟฟ้าอย่างเป็นทางการ]
21. "Fare cut boosts Purple Line riders, but still below target".
22. (12 July 2017). "Purple Line to connect with MRT on Aug 11". Bangkok Post.
23. (11 August 2017). "เปิดวิ่งเชื่อมต่อสถานีเตาปูน-บางซื่อ 12.00 วันนี้".
24. (4 September 2013). "รถไฟฟ้าสายสีม่วงคืบหน้าแล้วกว่า70%".
25. "Purple Line O&M contract (PDF)".
26. 'Purple Line deal agreed BEM signs 30-year contract with MRTA'. ''Bangkok Post'', 5 September 2013
27. (22 October 2012). "Bangkok Purple Line contract awarded". International Railway Gazette.
28. (21 August 2015). "BMCLอนุมัติเซ็นสัญญารถไฟฟ้าสายสีม่วงสัญญาที่5".
29. (17 May 2012). "ITD closer to Purple Line contract". The Nation.
30. isranews. (2012-10-04). "รฟม.จ้างอิตาเลียนไทยฯสร้างรถไฟฟ้า".
31. (22 April 2022). "Construction of southern Purple Line to begin in August". The Nation.
32. http://www.bangkokpost.com/archive/b358bn-rail-projects-expected-to-go-ahead/1256406. ''Bangkok Post'', 26 May 2017
33. (25 July 2017). "ครม.ไฟเขียวรถไฟฟ้าม่วงใต้ 1.101 แสนล้าน "อาคม" จ่อชงอีก 4 สายครบโครงข่าย".
34. [https://web.archive.org/web/20170725200757/http://www.nationmultimedia.com/detail/Economy/30321793 The Nation] ''The Nation'', 25 July 2017
35. https://www.bangkokpost.com/archive/purple-line-south-link-bid-faces-delay/1357647. ''Bangkok Post'', 10 Nov 2017
36. https://www.bangkokpost.com/news/transport/1541274/tor-for-slate-of-transport-projects-set-for-fast-track. ''Bangkok Post'', 17 September 2018
37. (12 December 2018). "Purple Line, Phuket light rail among projects up for PPP". Bangkok Post.
38. Member Yappofloyd meeting with MRTA Planning Division on 7 August 2019 at MRTA Headquarters
39. "'ศักดิ์สยาม'สั่งลุยเปิดประมูลรถไฟฟ้าสายสีส้ม-ม่วงใต้ภายในปีนี้".
40. เช็กคืบหน้ารถไฟฟ้าทุกสี ต้นปี 64 เปิดประมูล สีม่วง “เตาปูน-ราษฎร์บูรณะ. ''Prachachat'', 1 December 2020
41. (30 October 2020). "Tangled lines". Bangkok Post.
42. (10 November 2021). "REANNOUCEMENT OF INVITATION TO TENDER THE MRT Purple Line Project, Tao Pun - Rat Burana (Kanchanapisek Road) Section".
43. (11 March 2022). "Purple Line southern section construction to start this year".
44. (25 April 2022). "ประมูลคุมงานก่อสร้าง"สีม่วงใต้"คึกคัก บริษัทที่ปรึกษาแห่ยื่นชิงเค้ก 2.8 พันล้าน".
45. (2 August 2022). "รฟม. ส่งมอบพื้นที่ชุดแรกสร้างรถไฟฟ้า "สีม่วงใต้" สัญญา 3-4 แล้ว". Daily News.
46. "เปิดไซต์ก่อสร้างรถไฟฟ้า 4 สาย ส้ม เหลือง ชมพู คืบเกิน 90% สีม่วง เตาปูน-ราษฎร์บูรณะ เดินหน้าแล้ว 3.42%". Matichon.
47. (8 December 2022). "MRT Purple Line construction update December 2022". MRTA PR Facebook.
48. (8 March 2023). "MRT Purple Line construction update March 2023". MRTA PR Facebook.
49. (8 June 2023). "MRT Purple Line construction update June 2023". MRTA PR Facebook.
50. (May 12, 2020). "Purple Line extension 50% done".
51. https://m.facebook.com/story.php?story_fbid=1292441425666422&id=100047017301335
52. https://www.dailynews.co.th/news/4986011/
53. (24 September 2025). "Huge subsidence on Samsen Rd in Bangkok". Bangkok Post.
54. (24 September 2025). "Samsen Rd sinkhole: subsidence seen near MRT project". The Nation Thailand.
55. "รายละเอียดโครงการ {{!}} โครงการรถไฟฟ้าสายสีม่วง ช่วงเตาปูน-ราษฎร์บูรณะ (วงแหวนกาญจนาภิเษก)".
56. https://www.mrta-purplelinesouth.com/home_progress
57. (10 July 2025). "ส่องตำแหน่งที่ตั้งสถานีรถไฟฟ้า "สายสีม่วงใต้" พร้อมอัปเดต % สถานะการก่อสร้างล่าสุด! [กรกฎาคม 2568] — LivingPop".
58. 'Japanese firms win Purple Line deal'. ''Bangkok Post'', 6 November 2013
59. (23 September 2014). "First Sustina export order". International Railway Gazette.
60. "Bombardier Contributes to Increased Connectivity Across Bangkok".
61. "MRT Purple Line Train Timetable".
62. "Fare cut boosts Purple Line riders, but still below target - Bangkok Post Property finance advice".
63. (8 September 2017). "Purple Line use up 47% since 'missing link' completed". Bangkok Post.
64. http://www.thansettakij.com/content/309472. ''Thansettakij'', 27 August 2018
65. "Minisery of rail transport.".
66. "รฟม. ลดค่าโดยสารรถไฟฟ้า MRT สายสีม่วง สูงสุดไม่เกิน 20 บาท เริ่ม 16 ตุลาคม 2566 ตั้งแต่เวลา 11.00 น. เป็นต้นไป เพื่อลดภาระค่าครองชีพแก่ประชาชนตามนโยบายรัฐบาล".
67. Boyle, Gary. (2025-01-25). "PM orders week of free public transport to combat PM2.5". Bangkok Post.
68. "สถิติจำนวนผู้โดยสารโครงการรถไฟฟ้ามหานคร สายฉลองรัชธรรม (สีม่วง)".
69. (2025-03-29). "รถไฟฟ้า BTS และ MRT เปิดปกติแล้ว ยกเว้น สายสีเหลือง-สายสีชมพู ปิดต่ออีก 1 วัน".
70. (2025-11-06). "ปริมาณผู้ใช้บริการระบบขนส่งทางราง ประจำเดือนตุลาคม 2568".
71. (2025-12-05). "ปริมาณผู้ใช้บริการระบบขนส่งทางราง ประจำเดือนพฤศจิกายน 2568".
72. "Facebook".
73. (2025-09-22). "End of the Line: Bangkok's 20 Baht Flat Fare Policy to Conclude".
74. "Govt apologises for delaying Bt20 Bangkok-wide train fares until November".
75. "อัตราค่าโดยสาร".
76. Reporters, Online. (2025-10-30). "B40 daily flat fare approved for Red and Purple lines". Bangkok Post.
77. (2025-03-28). "Train services suspended for safety after earthquake in Myanmar".
78. español, Leer en. (2025-09-24). "A Bangkok road collapse creates a sinkhole disrupting traffic and prompting evacuations".
79. (2025-09-24). "Thailand works to tackle massive sinkhole in capital". Reuters.
80. (2025-09-26). "Bangkok Sinkhole Repair Halted After 1,500 Tonnes of Concrete Leak into Tunnel".
81. (2025-09-24). "Large Hole Swallows Road in Bangkok After a Subway Tunnel Collapses".