EXAT’s planned 6.7km Bangkok tunnel wins high public approval score
The Expressway Authority of Thailand (EXAT) will propose the construction of an underground tunnel to bypass the heavily congested Kaset-Nawamin intersection in Bangkok’s Bueng Kum district.
At the estimated cost of 36 billion baht, the tunnel will help motorists reach the Prasert Manukit Road with ease, EXAT governor Surachet Laophulsuk said on Tuesday, adding that the road leads to the Outer Ring Road and the northern section of the third-stage expressway system.
He said the tunnel’s entrance will be at the intersection between Sirat Expressway and Ngamwongwan Road. The 6.7-kilometre underground route will run along Ngamwongwan Road and bypass Phong Phet, Bang Khen and Kasetsart intersections before merging with the Prasert Manukit Road.
EXAT has just completed its second round of public hearing sessions for the project, which showed an approval score of 82.5 on the selected route, Surachet added.
After completion, the tunnel will be Thailand’s first underground expressway that features two layers of roads, each with two traffic lanes at a total width of 16 metres.
The 44-metre-deep tunnel will be complete with a ventilation system and four evacuation points. EXAT expects to finish the project’s feasibility study next year, and the estimated bidding will start two years later once it receives the Cabinet’s approval. Construction is expected to begin in 2027 and will take some five years to complete.
The tunnel should help drain some 70,000 vehicles per day from Ngamwongwan Road and connecting roads, while the capacity of the entire tunnel route is 140,000 vehicles per day, Surachet said.
