74-billion-baht Samui sea bridge set for 2029, 400 billion baht economic boost forecast

2026-02-13 - 08:46

SURAT THANI — The Expressway Authority of Thailand (EXAT) has unveiled the final study results for the proposed 74-billion-baht Samui Expressway project, a 37.41-kilometer route linking the mainland to Koh Samui via a 22-kilometer sea bridge. EXAT Governor Surachet Laophulsuk on 13 Febuary chaired the third public hearing at the Surat Thani Rajabhat University’s Samui Campus, presenting findings on engineering feasibility, economic returns, financial viability, and environmental impacts. The four-lane expressway will begin at Highway 4142 in Don Sak district, pass through Khanom district in Nakhon Si Thammarat, and connect to Highway 4170 on Koh Samui. Its centerpiece is a cable-stayed bridge spanning 22 kilometers across the Gulf of Thailand, with a clearance of at least 50 meters to allow large vessels to pass in line with international standards. The project is expected to cut travel time between the mainland and Koh Samui from about two hours by ferry to roughly 20 minutes by road. It would operate 24 hours a day, eliminating current limitations on nighttime travel. A willingness-to-pay survey found most motorists are prepared to pay between 1,000 and 1,200 baht per four-wheel vehicle per trip, which EXAT says reflects the value placed on convenience and time savings. The bridge will also integrate utility infrastructure, carrying electricity, water supply and telecommunications systems to enhance stability of essential services on the island. Surachet said the route passes through Category 5 watershed areas and would not affect upstream water sources. Strict dust and noise mitigation measures will be implemented during construction. Land expropriation remains a key public concern. EXAT pledged fair compensation based on official appraisal and current market prices, with a formal appeals process available. Over a 30-year period, the project is projected to generate up to 400 billion baht in economic circulation through tourism, employment and logistics, according to preliminary estimates. EXAT stressed that motorcycles will not be permitted on the bridge due to safety risks. The structure will stand more than 50 meters above sea level — equivalent to a 15- to 20-story building — where strong sea winds could destabilize smaller vehicles. Alternative options such as ferry services or motorcycle transport carriers are being considered. Under the current timeline, the project will be proposed to the EXAT board and the Transport Ministry this year, followed by an Environmental Impact Assessment (EIA). Cabinet approval is expected by 2027, after which the project would proceed under a public-private partnership (PPP) model. Construction is tentatively targeted to begin in 2029, with operations projected by late 2033.