Thailand’s Mass Rapid Transit Authority (MRTA) has selected the winning bidders for two civil works contracts under the Red Line commuter rail expansion. Unique Engineering and Construction Private Limited won the Dark Red Line extension from Rangsit to Thammasat University with a bid of THB6.057 billion, while a joint venture between Unique Engineering and Construction Plc and Trusty Construction Co Ltd secured the Light Red Line Siriraj–Taling Chan–Salaya section with a bid of THB14.72 billion.
The Dark Red Line extension will cover 8.84 km and will be constructed entirely at ground level. The Light Red Line contract consolidates previously planned sections into a single 20.5 km package and includes three new stations: Rama VI, Bang Kruai–EGAT, and Baan Chim Phli.
The Red Line expansion forms part of Bangkok’s suburban rail development programme aimed at improving regional connectivity. Construction of both extensions is expected to take 36 months, with completion targeted for February 2029 and passenger services planned to begin in March 2029, subject to final contract negotiations and approvals.