Ge takes turns with his colleagues to make deliveries on the "sky route".

"Because the route is so long, the meals we often take with us in the morning are too cold to eat when we are ready to have breakfast," Ge said.

Last year, a river at an altitude of 4,570 meters blocked Ge's way after flooding a road on the route.

"I was stranded there for three days," he said.

For Ge, taking the route is mostly about "driving in the daylight and watching stars at night". Sometimes, he encounters injured wild animals like Tibetan antelopes on the road. He then contacts local wildlife rescuers to help them.

Ge has also helped some people on his way. In 2012, he found a cyclist from Taiwan who had passed out. He helped the man into his van and treated his injuries with a first-aid kit.

"In very remote areas of China, delivery services are mostly only provided by China Post," Ge said.

"I may be alone on the long road, but I am proud of my job."