Viaduct with larger spans, typically lack sufficient horizontal and vertical clearance for large ships. See the Chesapeake Bay Bridge-Tunnel. The Millau Viaduct is a cable-stayed road-bridge that spans the valley of the river Tarn near Millau in southern France. Designed by the French bridge engineer Michel Virlogeux, in collaboration with architect Norman Robert Foster, it is the tallest vehicular bridge in the world, with one pier's summit at 343 metres (1,125 ft)—slightly taller than the Eiffel Tower and only 38 m (125 ft) shorter than the Empire State Building. It was formally dedicated on 14 December 2004 and opened to traffic
Millau Viaduct speed of construction then rapidly increased. Every three days, each pylon increased in height by . This performance was mainly due to sliding shuttering. Thanks to a system of shoe anchorages and fixed rails in the heart of the pylons, a new layer of concrete could be poured every 20 minutes. The bridge road deck was constructed on land at the ends of the Viaduct, and rolled lengthwise from one pylon to the next, with eight temporary towers providing additional support. The movement was accomplished by a computer-controlled system of pairs of wedges under the deck; the upper and lower