A bridge across the mountain gap

Before the bridge, the road did the crossing, and the road needed four hours. The gap at Aizhai is the point where the ridge west of Jishou breaks the route toward Chadong and the Guizhou border — the old highway twisted down one wall of the Dehang gorge and up the other, and the run from Jishou to Chadong took half a working day. The geography that made the road slow made the crossing obvious: a narrow gorge, sound rock on either side, and a straight line available to anything that could fly. The G65 Baotou-Maoming expressway — built here as part of the trunk road from Chongqing toward Changsha — needed exactly that line for its Jishou to Chadong section, and the key works of the section were thrown across the canyon at Aizhai town. It is a measure of how short this country is of flat ground that the expressway package around the bridge, sixty-four kilometres of new road, is two-thirds bridges and tunnels, with another 129 kilometres of local roads upgraded alongside it. The gap had always been crossed; the question was whether it could be crossed in minutes instead of hours, by a road that did not close with the ice and the fog of the ridge each winter.

The numbers are world scale. The main span runs 1,176 metres between anchorages, with the deck standing 336 metres high by international measurement — Chinese figures put it 355 metres above the canyon floor — and at completion the bridge ranked among the highest on earth while carrying the longest main span of any of the world's four hundred or so highest bridges. It is a steel truss suspension bridge, and Chinese engineering describes it as the largest canyon span of that type in the world, its deck 24.5 metres wide carrying four lanes and 1,888 lights for the night. It is also, distinctly, a tunnel-to-tunnel bridge: the deck runs from one mountainside portal straight to the other, and it was the highest and longest of that kind anywhere when built. Construction began in October 2007, the truss closed in August 2011, walkers were let on during the 2012 spring festival, and traffic crossed from 31 March 2012. The Asian Development Bank lent 208 million dollars of a 610-million-dollar project that bought the whole road, not the monument alone. In September 2012 more than forty jumpers from thirteen countries leapt from it in an international BASE festival, the first sports event the span hosted.

What the bridge changed is measured in hours. Travel between Jishou and Chadong, four hours on the old road, fell to less than one — a regrading of daily life for the mountain townships on both sides, whose markets, schools and hospitals now sit within the hour of the prefecture capital. The G65's route past the bridge also passes Shibadong village, and official writing calls this stretch of expressway a prosperity corridor through the Wuling mountains, the region it serves having been for decades the standard example of isolated western hill country. The construction industry spent the following decade collecting honours for the span, ending with China's Zhan Tianyou civil engineering prize in 2020, and the bridge remains famous for something no statistic records: the view from the deck, over the gorge, the stream and the villages of Dehang, from a height the old road never offered except to birds. The lights keep it open at night, and the scenic area grown up around it has made the crossing itself a destination — visitors now come to stand on the bridge that ended the four-hour drive, and the drive survives as a story the region's grandparents tell.