The "Mikuni Tunnel" that connects Gunma and Niigata prefectures has been aging, so it has finished its role for more than 60 years, and from the 19th, the "New Mikuni Tunnel", which has become wider and safer, will open.
The "Mikuni Tunnel" on National Highway No. 17, which connects Minakami Town in Gunma Prefecture and Yuzawa Town in Niigata Prefecture, was opened in 1959 and is indispensable for connecting Gunma and Niigata, as many large trucks for logistics are used. It is one of the roads.
However, due to aging and corrosion caused by acidic spring water entering from the mountains, repeated reinforcement work resulted in narrow roads and difficulty in passing large vehicles.
For this reason, the Ministry of Land, Infrastructure, Transport and Tourism has been constructing a new "New Mikuni Tunnel" next to it for nine years, and will open on the 19th.
The new tunnel has the same overall length as 1.2 km, but the road width is 3 meters wider and the concrete is 1.5 times thicker than before, making it difficult for spring water to enter.
Mitsuhiro Ito, Construction Supervisor of the Takasaki River National Highway Office of the Ministry of Land, Infrastructure, Transport and Tourism, said, "Since it is an important arterial road connecting Kanto and Shinetsu, we would like to continue to build safe and secure roads."