Zhongnanshan Tunnel, China
Running through the Qinling Mountains in Shaanxi province of China, lies the Zhongnanshan tunnel, a twin-tube channel. The road tunnel spans 18.02 kilometers or 11.2 miles, about twice the height of Mount Everest. After about five years of construction and $410m spent, the road tunnel opened in 2007 to members of the public. On average, the two tubes of road tunnel facilitate vehicles to travel on four lanes at maximum speeds of 80 km/h.
Photo Credit: Aydinlatma.org
All the 6m-high tubes are well differentiated with brightly colored and patterned lighting to ensure that drivers always stay alert and reduce eye strain while on the road.