Purple Line (Bangkok)

Officially named the Chalong Ratchadham Line (Thai: สายฉลองรัชธรรม) – "To Celebrate the Great King's Reign with Righteousness"[4] – but informally known as the "Purple Line", the rapid transit system serves a north-south corridor in Bangkok's Mass Rapid Transit Master Plan. It incorporates an extension of the Blue Line from nearby Bang Sue station to Tao Poon station.

The construction project was divided into six contracts, three of them civil work. The contracts were signed from late 2009 to early 2010 and completion was originally scheduled for 2014.[5][6][7][8] 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.[9][10]

The 2011 Thailand floods delayed the construction of the line, and in June of 2013, five people were injured when six beams fell onto vehicles below Tao Poon station.[18] In July 2014, the civil work was 94 percent complete;[19][20] in October 2014, civil work was stated to be 99% complete.[21]

The line was opened on 6 August 2016.[3] However, the Blue Line extension section was delayed, so when it opened the Purple Line wasn't connect to any other rapid transit system in Bangkok. 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.[22]

The Blue Line extension to Tao Poon was opened about a year later, on 11 August 2017,[23][24] and ridership increased. In 2019, daily ridership for the line was 70,000.[1][2]

• 
  MRT Purple Line under construction
• 
  Flooding of MRT Purple Line construction site in 2011
• 
  The MRT Purple Line platform at Khlong Bang Phai MRT Station
• 
  MRT Purple Line route map at Tao Poon Station (14 August 2016)

*Only stations that are already open for public use are shown in this table.

Bangkok's Mass Rapid Transit Master Plan includes extending Purple Line south from Tao Poon to Rat Burana through Bangkok's old town via both an underground and elevated route. The total planned length is 23.5 km (12.7 km underground, 10 km elevated and 0.8 km transitioning structure) with seventeen stations (ten underground and seven elevated).[33]

Station names are as per report published in 2019, are subject to change and are not finalized. Stations locations may be adjusted

Approval was expected in mid 2017 with a tender due in the second half of 2017.[34] On 25 July 2017, Cabinet approval was given,[35][36] but the tender was then delayed until 2018.[37][38] By December 2018, a tender had still not been issued and was further delayed.[39] In August 2019, subject to final land acquisition, a March 2020 tender was planned.[40] In mid 2020, the Ministry of Transport still aimed for a tendering process within 2020 despite COVID-19 related delays.[41] The MRTA expected the tender to be issued in February 2021.[42] If construction commences in the second half of 2021, the extension is projected to enter service in 2027.[43]

A 4.5 km extension from Bang Yai to Bang Bua Thong intersection - which was not part of the original Purple Line plan - has previously been requested by the Nonthaburi governor.[44] However, as of 2020 there are no plans to build such an extension.

OTP has previously indicated in 2008 that a southern cross-river connection could be built between Samrong and Rat Burana either by extending the MRT Yellow Line or by extending the Purple line. However, such an extension would only be considered after 2029 once all other planned lines are fully operational.