A walk in the clouds

"The microclimate here is extreme," says Zhang Yongjian, a former deputy chief engineer of the bridge project.

Fog blankets the area for nearly half the year. Winter temperatures on the mountain run five degrees lower than in the valley below, sharply limiting the construction window, Zhang adds.

After three years of planning, the engineers arrived at a solution. They separated the towers from the deck. The towers were placed on the peaks, while the deck was suspended below.

This single innovation reduced excavation by 700,000 cubic meters — enough earth to fill a soccer field to the height of a 20-story building.

"This design adapted to the terrain and protected the natural environment on both sides," Zhang says.

When the bridge opened on March 31, 2012, the transformation was immediate: a journey that once took 30 minutes was reduced to just one minute.