National Highway 318 is the longest highway in China
China National Highway 318 (G318) is a challenging road running from Shanghai to Zhangmu, the westernmost border with Nepal. It is said to be the longest highway in China.
The road, also known as Shanghai Tibet Highway, is 5.476 kilometres (3,403 miles) long. Crossing over eight provinces, the road runs from Shanghai to Zhangmu on the border with Nepal. The state of this road leading into Tibet was one of the major reasons to build the Tibetan railway system to Lhasa, locals say this section of the road has four seasons per day, freezing, cool, warm, hot, which leads to needless injuries.
Adverse weather conditions are common. Ice and snow can be on the way. One notable section of this road is the Si Du River Bridge, the bridge with the greatest vertical clearance in the world as of its 2009 completion. From Lhasa to Zhangmu it is also called Friendship Highway. The 115 km. continuation to Kathmandu is named Arniko Rajmarg. Tibet naturally has some of the harshest terrain in the world, so it’s not likely to have the best roads leading in and out. The highest point on this road is just less than 4,000m.