The State Railway of Thailand has opened electronic bidding for two Red Line suburban rail extension projects with a combined construction value exceeding 20.79 billion baht ($660 million), marking an acceleration of the government’s metropolitan infrastructure development program.
The acting governor of the State Railway of Thailand announced that tender documents are available through December 28, with electronic bid submissions scheduled for December 29 via the government e-procurement system. Contract signing is expected in February 2026, with construction commencing the following month and completion targeted for March 2029.
The Dark Red Line extension from Rangsit to Thammasat University Rangsit Campus carries a construction budget of 6.06 billion baht ($190 million) within an approved framework of 6.47 billion baht ($210 million). The 8.84-kilometer ground-level alignment will add four stations: Khlong Nueng, Bangkok University, Chiang Rak, and Thammasat University Rangsit Campus. The project, approved by cabinet in January 2025, requires expropriation of approximately 14 rai (22,400 square metres), with the related decree expected by February 2026.
The Light Red Line extension from Siriraj Hospital to Salaya has a construction budget of 14.73 billion baht (470 million) under an approved framework of 15.18 billion baht (480 million). The 20.5-kilometer project includes both elevated and ground-level sections with nine stations plus three additional infill stations at Rama VI Bridge, Bang Kruai-EGAT, and Ban Chimphli. Cabinet approved this project in June 2025. The alignment utilizes existing State Railway of Thailand land, eliminating expropriation requirements.
Both projects operate on a 36-month construction timeline. The extensions follow directives from the Ministry of Transport issued in October 2025 to accelerate approved rail infrastructure projects. The Red Line currently operates two branches from Krung Thep Aphiwat Central Terminal to Rangsit and Taling Chan, serving commuters in the greater Bangkok metropolitan area.
