Locals resist Bangkok tunnel option on Kaset-Nawamin Road
Underground expressway to cost $50bn
Residents have opposed the Expressway Authority of Thailand (Exat)’s proposal to construct an underground route to replace a controversial section of the N1 Expressway development after a 17-month initial feasibility study.
Exat held a third hearing on the project at a hotel in Bangkok’s Chatuchak district on Saturday, attended by more than 50 residents.
Manawat Kamolsilp, a resident, said that building the underground route would cost about 50 billion baht, compared to 17 billion baht for the elevated expressway.
“It is not justified to spend more on the underground route. The underpass will be cheaper to build and easier to link with other projects.
“Maintenance costs for the elevated expressway will be lower, and toll fees will also be cheaper,” he said.
Lt Gen Mahatthana Kamolsilp, another resident, said locals had their land expropriated for the expressway construction project several years ago, and more land would likely need to be expropriated from them for the planned underground route. Some were unlikely to welcome the imposition.
Exat governor Surachet Laophulsuk said on Saturday that Exat will finalise the project details for submission to the Transport Ministry for consideration before seeking cabinet approval for the undertaking.
An environmental impact assessment is expected to be conducted early next year.
If approved by the cabinet, bidding is tentatively scheduled for 2026, with construction to follow the next year.
Mr Surachet previously mentioned the agency had considered several aspects, including engineering, investment costs, and the environmental impact, and found the underpass to be the most feasible option.
The 6.3-kilometre underpass, which will be the country’s first expressway tunnel, will run along Ngarmwongwan Road via Phongphet Intersection, Bang Khen Intersection, and Kaset Intersection to Prasertmanukit Road before connecting with the N2 Expressway.
The tunnel, which is built in a cut and cover structure, will have an entry point and exit with a length of 1.75km, as well as an elevated structure with a length of 2.49km to link with the N2-phase expressway.
“The tunnel will be over 40 metres tall, about the height of a 10-storey building,” Mr Surachet said.
Mr Surachet added the N2 and N1 sections will only be open to four-wheel vehicles due to it being built on foundation pillars installed on Prasertmanukit Road, also known as Kaset Navawin Road, 25 years ago.
He said construction of the tunnel and other related structures would cost an estimated 49 billion baht.
Of this amount, 44.5 billion will be spent on construction, 3.6 billion baht will be allocated for land expropriation costs, and 1.06 billion baht will be earmarked for construction supervision.
Exat is financially sound and is considering investing in the project itself, he said, adding that the agency may issue bonds to raise funds for construction.
Construction is expected to take about five years, with an estimated traffic volume of 70,000 vehicles per day in the first year of operation, half of the route’s total capacity.
Mr Surachet expressed confidence the proposed underpass would address environmental concerns raised about the previous design.
He mentioned that the northern part of the three-phase expressway development is divided into two stages.
The first stage, which is called the N2, spans from Prasertmanukit Road to the eastern Outer Ring Road, covering 11.3 km with an investment cost of 16.9 billion baht.
For the second stage, N1, Exat conducted a feasibility study of alternative routes to replace the controversial section and settled on the underpass following discussions with Kasetsart University and communities along the planned route.
Source: https://www.bangkokpost.com/thailand/general/2828648/locals-resist-exats-city-tunnel-option
