GUIYANG -- The karst mountains of Guizhou province in Southwest China feature ravines so deep that locals call them "the Earth's cracks." At Huajiang town, the Beipan River carves one such gorge, a relic of Triassic seas, etched into limestone cliffs, which once marked the limits of human passage.

Today, this chasm is no longer an insurmountable barrier to human travel. The Huajiang Grand Canyon Bridge, poised to become the tallest in the world, stretches across this abyss with its final test just completed on Monday. It was a load test for the weight of traffic on the bridge -- and it proved successful, thereby representing another big step in the quest to transform isolation into connection.

This load test, considered the final step before the bridge welcomes traffic, included both static and dynamic tests.

Ninety-six heavy trucks, weighing a combined 3,300 tonnes, rumbled in batches onto the deck in slow procession, parking at designated spots. Over 400 sensors across the bridge were tracking the tiniest shifts in the main span, towers, cables and suspenders.