By ashleykaren
The Expressway Authority of Thailand (EXAT) has submitted an underground route to substitute a controversial section of the N1 Expressway development following a 17-month initial feasibility study.
Speaking at the second hearing on the project, the head of EXAT, Surachet Laophulsuk, declared that the agency had evaluated several aspects, comprising engineering, investment costs, and environmental impact, and found the tunnel the most feasible.
The 6.7km tunnel, which will be the country’s first expressway underpass, will operate along Ngarmwongwan Road through Phongphet Intersection, Bang Khen Intersection, and Kaset Intersection to Prasertmanukit Road before linking with the N2 Expressway.
He stated that the tunnel, one of three possibilities under study, has a total score of 82.5 with a calculated investment cost of 36 billion baht and an economic internal return rate of 17%.
Mr. Surachet also added that EXAT is in good financial health and is contemplating investing in the project itself, and continued that the agency may consider allocating bonds to increase money to finance the construction.
He expressed the environmental impact assessment will be wrapped up in May next year for submission to the cabinet for permission. A bidding is tentatively planned for 2026, with construction to follow the next year.
Construction will possibly take approximately five years, and in the first year of commencement, traffic volume is counted at 70,000 vehicles per day, half of the route’s total capacity.
Mr. Surachet also confidently said that the proposed tunnel would be authorized by those who had environmental concerns about the prior design.
He mentioned that the northern part of the three-phase expressway development is divided into two stages. The first stage, N2, operates from Prasertmanukit Road to the eastern Outer Ring Road, with a length of 11.3 km and an investment cost of 16.9 billion baht. The project is ready and will be presented to the new government for permission soon.
For the second stage, N1, EXAT has performed the feasibility study of alternative routes to substitute the controversial section and come up with the underpass following discussions with Kasetsart University and communities along the scheduled path.
