The 678-kilometre routes were part of a total of seven double-track railway megaprojects. They include the 168.2km Chumporn-Surat Thani route, costing 30.4 billion baht; the 321km Surat Thani-Songkhla route (66.2 billion baht); and the 189km Denchai-Chiang Mai route.
All seven routes are worth more than 270 billion baht.
After approval, the SRT board said it is now in the process of submitting the project report to the Transportation Ministry by the end of June before seeking feedback from various agencies, including the Office of the National Economic and Social Development Council (NESDC).
The process involves reviewing the approval of funding sources, which could include both domestic and international loans, as well as a portion of this fiscal year's budget.
SRT estimated that the initiative for its final three projects would be presented to the Cabinet for further approval between July and October.
If this megaproject is approved, the State Railway of Thailand will issue a Royal Decree on Land Expropriation from November 2023 to August 2025, before beginning the survey and valuation of real estate. This is expected to be completed by May 2025, and the process of arranging land ownership will begin between June 2026 and May 2027.
Along with the aforementioned process, SRT stated that it will proceed with its planned process of implementing these projects, which includes the preparation of terms of reference (TOR) to procure civil construction contractors. The procurement would begin in November, with the tender being completed by May 2025.
The contractor will be urged to begin construction on the project immediately. The project will take about five to six years to complete and launch in 2031.
In addition, the SRT revealed the most recent progress of the Khon Kaen-Nong Khai double-track routes, for which the board had announced the means and conditions of electronic bidding with a median price of 28.7 billion baht on June 21.
The e-bidding process is expected to be completed in October, allowing construction to begin early next year and open by the end of 2027.
The double-track railway system is the country's ambitious plan to improve railway logistics and transportation efficiency. The project is expected to help reduce travel time to Thailand's southern part by at least 30%, and many routes by up to two hours.
Meanwhile, the railway upgrade will save energy, reduce pollution, and improve connections to neighbouring countries.