A bridge officially designated the tallest in the world is to be inaugurated in southern France -- a spectacular feat of engineering that will carry motorists at 270 metres (885 feet) above the valley of the river Tarn.

Designed by British architect Norman Foster, the Millau motorway viaduct stretches for 2.46 kilometres (1.6 miles) between two plateaux in the Massif Central mountain range and when it opens Thursday will remove one of the country’s most notorious traffic bottlenecks. Built of steel and concrete at a cost of 390 million euros (520 million dollars), the bridge rests on seven pillars, one of which -- dubbed P2 -- climbs to 343 metres above ground level, making it 23 metres higher than the Eiffel Tower.

Like a taut thread pierced by a line of needles, the silhouette dominates the countryside for miles around and has been praised as a classic marriage of aesthetics and science. More than 60,000 people have already paid for tours of the construction site. "A work of man must fuse with nature. The pillars had to look almost organic, like they had grown from the earth," Foster said.

The bridge was commissioned in order to open up a new north-south route across central France and relieve pressure from lorry-drivers and tourists bound for the Mediterranean and Spain in the saturated Rhone valley corridor to the east. Eiffage is predicting an average of 10,000 vehicles per day, with a peak of 25,000 during the summer season when tariffs will be increased. If the bridge proves unexpectedly profitable, the French state has the right to take possession from 2044.

辅助阅读：法国“世界最高桥梁”即将通行无阻。一座经官方认可的“世界最高桥梁”即将在法国南部举行落成典礼，随着这座外观宏伟、设计精湛的建筑工程的竣工，开车人可以从塔恩河上方270米（885英尺）处横跨塔恩河河谷。