Red Line extensions go to tender, set to inject billions into rail investment
Thailand is moving ahead with tenders for two Red Line commuter rail extensions under the M-MAP2 plan, with contracts expected by February 2026 and services targeted to start in March 2029.
The Red Line commuter rail extensions are among the projects under Phase 2 of the Mass Rapid Transit Master Plan in Bangkok and its vicinity (M-MAP2), grouped under A1 (ready to proceed immediately). The package includes:
- Red Line: Rangsit-Thammasat University (Rangsit Campus), 8.84 km, budget 6.473 billion baht
- Red Line: Siriraj-Taling Chan-Salaya, 20.5 km, budget 15.176 billion baht
- Light Red Line: Bang Sue-Phaya Thai-Makkasan-Hua Mak and Dark Red Line: Bang Sue-Hua Lamphong (Missing Link), 25.9 km, budget 34.95 billion baht
In 2026, the Red Line extensions are expected to become a flagship project of the Transport Ministry, aimed at driving more than 20 billion baht in investment. At present, the State Railway of Thailand (SRT) has already submitted two routes for Cabinet consideration and has begun the tender process via electronic bidding (e-bidding):
- Red Line: Rangsit-Thammasat University (Rangsit Campus)
- Red Line: Siriraj-Taling Chan-Salaya
The SRT listed the e-bidding tenders on the government procurement platform (e-GP) on December 29, 2025. It expects to announce the winning bidders for both projects and sign the contracts by February 2026. Once contracts are signed, the SRT will issue a Notice to Proceed (NTP) in March 2026.
Construction is scheduled to take 36 months, with completion targeted for February 2029, and service expected to begin in March 2029.
Rangsit-Thammasat University (Rangsit Campus) extension
The 8.84-km extension, with a budget of 6.473 billion baht, will run through Mueang Pathum Thani, Thanyaburi, and Khlong Luang districts in Pathum Thani province, terminating at Thammasat Rangsit Station. It will include five stations:
- Rangsit
- Khlong Nueng
- Bangkok University
- Chiang Rak
- Thammasat Rangsit
Siriraj-Taling Chan-Salaya extension
The 20.5-km extension, with a budget of 15.176 billion baht, will extend westward from Taling Chan Station to Salaya Station, with an additional alignment to Siriraj. It will include eight stations:
- Siriraj
- Charan Sanitwong
- Taling Chan Floating Market
- Taling Chan
- Ban Chimphli
- Kanchanaphisek
- Sala Thammasop
- Salaya
