Highway drives Metog's economic engine

Zhang Shuisheng, a driver who has navigated the route frequently since 2013, said it's probably the only highway in China that still needs such regulation, which shows how challenging the road is.

"Efforts to upgrade the highway have never stopped over the past decade. Getting to Metog has become much easier and safer. And the transformation of the county in such a short time is unbelievable," said Zhang.

For the people of the Monba ethnic group who live along the Yarlung Zangbo River canyon, where the snow-capped peaks give way to lush subtropical forests, the road has unlocked a viable agricultural sector.

Resident Drakpa makes a living by planting tea, bananas and other subtropical fruits on terraced fields in a village in the canyon.

"Like many villagers, I only learned to become a farmer since the road opened. What's the point of cultivating agricultural products when it's nearly impossible to ship them out?" Drakpa said.