|No.1 Zhongnan Mountain Highway Tunnel|
Qinling Mountain Zhongnan Mountain Highway Tunnel is the main project from Baotou to Maoming in the national expressway network.
It is also an important part of the crisscross highway network of "three vertical, four horizontal and five radial" from Xi'an to the Ankang highway.
The Single tunnel is 18.02 kilometers long, and the double tunnels have a total length of 36.04 kilometers.
The construction scale is the largest in the world, and it is at top of China highway tunnels that need 15 minutes to pass through.