Red Line Missing Link offers new hope for three-airport rail travel

Thailand’s long-delayed Red Line Missing Link project has returned to the spotlight as a possible rail solution for connecting Don Mueang, Suvarnabhumi and U-Tapao airports, as the high-speed rail link to the three airports faces growing uncertainty.

The suburban rail project covers the Bang Sue–Phaya Thai–Makkasan–Hua Mak section and the Bang Sue–Hua Lamphong section. If accelerated, it could allow the Red Line to connect with the Airport Rail Link and help maintain the wider plan for rail access between Bangkok and the Eastern Economic Corridor.

The Red Line Missing Link has gained fresh attention as the Eastern Economic Corridor Office (EECO) prepares to review the troubled high-speed rail project linking Don Mueang, Suvarnabhumi and U-Tapao airports, amid uncertainty over whether Asia Era One Co Ltd, the CP Group-linked winning bidder, can proceed.

The joint investment contract management committee will meet on July 15, 2026, before submitting proposals to the EEC Policy Committee, chaired by Prime Minister Anutin Charnvirakul. A working group comprising the EECO, the State Railway of Thailand (SRT) and Asia Era One is expected to present two options in August: amend the contract or terminate it.

Chula Sukmanop, secretary-general of the EECO, told Bangkokbiznews that if the EEC Policy Committee chooses to end the joint-investment contract with Asia Era One Co Ltd, there is currently no proposal to reopen bidding for the high-speed rail link to the three airports.

He noted that the original investment model had not attracted sufficient private-sector interest, while launching a new tender could take up to two years and further delay the EEC’s rail network.

The “best approach”, he argued, would be to make better use of existing assets by developing double-track rail and improving route connections.

Under this approach, the Red Line Missing Link should be expedited because it could connect the Red Line with the Airport Rail Link and support rail travel from Don Mueang to Suvarnabhumi and onward to U-Tapao.

The Missing Link project has been widely discussed over the past week. The SRT is currently seeking 110 million baht in binding budget commitments for fiscal years 2027 and 2028 to review the previous study and detailed design. The budget request comprises 22 million baht in 2027 and 88 million baht in 2028.

The SRT has already completed the draft terms of reference and estimated reference price for hiring a consultant. The documents are now being submitted to the SRT governor for approval.

The agency is confident it can speed up the process and seek Cabinet approval for the project before opening bidding by 2028.

The project is considered urgent not only because it would strengthen Bangkok’s rail network, but also because it could help eliminate level crossings along the route. The Missing Link alignment currently passes 13 crossings, including Pradiphat, Set Siri, Ranong, Nakhon Chai Si, Ratchawithi, Si Ayutthaya, Yommarat, Rama VI, Phaya Thai, Ratchaprarop, Asok, Ramkhamhaeng and Srinagarindra.

The Missing Link route is designed to cover 25.90 kilometres, comprising 22.40 kilometres of elevated track and 3.50 kilometres underground.

The project will include nine stations: Samsen, Ratchawithi, Yommarat, Yotse, Hua Lamphong, Phaya Thai, Makkasan, Ramkhamhaeng and Hua Mak.

The SRT’s earlier study was approved by the Cabinet on September 13, 2024. The approval covered an adjustment to the project’s investment framework from 44.15 billion baht to 44.57 billion baht.

The study estimated that the project would serve about 211,000 passenger trips per day during its initial phase of operation, rising to 330,000 trips per day in the future. It also projected an economic return of 29.91% and a financial return of 13%.

Source: 
Bangkokbiznews