The State Railway of Thailand (SRT) is preparing to submit draft amendments to the three-airport high-speed rail public-private partnership (PPP) contract for Cabinet approval in June 2026, with signing targeted for July 2026. The project links Don Mueang, Suvarnabhumi and U-Tapao airports and is being developed by Asia Era One Co., Ltd., led by Charoen Pokphand Group, under a contract signed in October 2019 with a proposed state co-investment of THB117.226 billion.
Under the proposed changes, the state’s Public Investment Cost payment will shift from a lump-sum payment of THB149.65 billion upon commencement of operations to instalment payments based on construction progress, capped at THB120 billion. In addition, the THB10.67109 billion concession fee for the Airport Rail Link investment rights will be paid in seven equal annual instalments, beginning on the signing date of the amended contract.
The SRT plans to submit the draft to the Cabinet in June 2026 and sign the amended agreement in July 2026. The Notice to Proceed is expected within 30 days of signing, followed by a five-year construction period and six months of system testing. The line is targeted to open in 2032.
The amendments are also necessary to coordinate shared civil works on the Bang Sue–Don Mueang section with the Thai–Chinese high-speed rail project. If the contract is not signed within the planned timeframe, the SRT may seek Cabinet approval to revise the scope and undertake the shared works under Contract 4-1 itself to avoid further delays.
