Construction started on May 22, 2024. The Na Pinh underground project across Ky Cung River connecting Na Pinh village, Tan Lien commune and Co Luong village, Gia Cat commune of Cao Loc district has been completed and opened to traffic since January 27, 2025.
Arriving at Na Pinh tunnel on the first working day after the Lunar New Year holiday of At Ty 2025 (February 3, 2025, the 6th day of the first lunar month), Lao Dong Newspaper reporters could see the joy and excitement of the people here.


Asked by reporters, Mr. Hoang Van Nghinh (62 years old, living in Na Pinh village) recalled that in the past, traveling and trading agricultural products for people in Na Pinh village and neighboring villages of Tan Lien commune was very difficult because the Ky Cung river divided the two banks.
Although the people had installed bamboo bridges many times, every flood season the bridges were washed away. After that, the people asked for railway tracks to build temporary bridges, but the bridges were very narrow, only enough for one motorbike to pass, and temporary bridges were never safe.

"To go to the city to sell agricultural products, people have to cross a temporary bridge, when it is dark or before dawn, walking while shaking, if not careful they will fall into the river. On flood days, to cross the river they have to go through Gia Cat bridge and then turn back, a distance of dozens of kilometers. Now, the Na Pinh underground project has been solidly built across Ky Cung river, making the villagers extremely excited" - Mr. Nghinh confided.
Mr. Hoang Van Hoat (32 years old, resident of Co Luong village, Gia Cat commune) - happily said: "My maternal grandparents' house is in An Dinh village, Tan Lien commune, near Na Pinh village, this year going to my grandparents' house for Tet is much easier than before, the newly built underground is very solid, we can travel with peace of mind. So, near my house this year there is a new and spacious National Highway 4B, the Na Ping underground that has been waiting for many years has been completed, it can be said that the joy is doubled".

According to the reporter's investigation, the Na Pinh underground project has a total investment of 4 billion VND from the district budget and socialized sources. Of which, teachers, staff, and parents of Ngoi Sao Hoang Mai Primary, Secondary, and High School (under Dong Do Hanoi Education Joint Stock Company) donated and sponsored 1.5 billion VND.
According to the design, the project has a total underground length and access road of 224m, including: Underground spillway combined with slab bridge 64m long, 5.5m wide with reinforced concrete structure, access roads on both sides of the underground end 160m long, roadbed 4m wide, road surface with cement concrete structure 3m wide.

On February 3, speaking with a reporter from Lao Dong Newspaper, Mr. Hoang Van Khanh - Chairman of the People's Committee of Tan Lien Commune, Cao Loc District - said that the construction and completion of the Na Pinh underground project is the long-standing wish of hundreds of households in Tan Lien Commune.
"During the construction process, the project has received the support of all people, many households have voluntarily donated land, creating conditions for the project to be completed soon and put into use.