CHINA—The Zhongnan Mountain Tunnel that passes through the Qinling mountain range opened for traffic on January 20. The tunnel is 18 kilometers (11.2 miles) long making it the world's second longest tunnel highway and the first of its kind in China. It was designed and constructed in China.
According to China News report, it took four years and nine months and 3.193 billion yuan (about US$400 million) to build the tunnel. The tunnel starts at the north section of the Xian-Ankang Highway, and ends at Yingpan township of Shangluo city in the south. It cuts through the Qinling Mountains, which divide the South and North of China and it only takes fifteen minutes to drive through.
The twin-tunnel highway allows an upper speed limit of 80 kilometers (50 miles) per hour. The length of each tunnel is 18.02 kilometers. The tunnels are equipped with advanced rescue, monitoring, and control systems.
In order to relieve the stress of driving in such a long tunnel there are three 150-meter-long special lighting areas in each tunnel where drivers can see scenes depicting “blue sky”, “white clouds” and “a rainbow.”