Thailand is not expected to proceed with the underground tunnel segment of the Phase 3 Northern Expressway project (N1 section) in Bangkok, owing to financial viability concerns.
An announcement in this connection came from Thailand’s Minister of Transport, Suriya Juangroongruangkit. The underground tunnel segment was intended to connect the Si Rat Expressway to Ngamwongwan Road and Prasert Manukit Road in Bangkok.
However, the Expressway Authority of Thailand (EXAT) cited a financial study indicating that the project would not generate sufficient financial returns, reported The Nation.
The N1 segment, designed to improve connectivity within northern Bangkok, faced challenges as its financial internal rate of return (FIRR) was found to be negative, despite an economic internal rate of return (EIRR) of 19.2%.
Minister Suriya, who also serves as Deputy Prime Minister, stated that EXAT requires projects to be financially viable.
According to the Minister, as an investment-driven organisation, EXAT demands that projects be financially viable in addition to being economically beneficial. Suriya also emphasised that securing a budget allocation from the Ministry of Transport would be essential to support both the construction and maintenance of the project.
The 10.55-km underground tunnel would extend from the Si Rat Expressway-Ngamwongwan Road intersection, passing through Ngam Wong Wan Road, Phongphet intersection, Bang Khen intersection, and Kaset intersection. It would then reach Prasert Manukit Road, where it would connect with the N2 section at Sukhonthasawat Junction.
The total cost of the project was estimated at THB49.22bn ($1.4bn), with THB44.5bn ($1.28bn) earmarked for construction, THB3.6bn ($103.2m) for land acquisition, and THB1.06bn ($28.8m) for construction oversight.
In response to opposition to an elevated expressway from local communities and Kasetsart University along the intended route, EXAT had initially considered the underground tunnel as an alternative. However, the projected high cost associated with this option ultimately led to its cancellation.
