Millau Viaduct

A viaduct is a long bridge that crosses a valley.

This one is in France. It is very high: in the photo, a low cloud hangs on the hill beside it.

The Millau Viaduct crosses the valley of the Tarn River beside the town of Millau, in southern France. It carries the A75 motorway, which links Clermont-Ferrand with Béziers in the south.

The bridge is 2,460 meters long, about two and a half kilometers. Its road deck sits about 300 meters above the river. One of its builders pointed out that this is the same as the height of the Eiffel Tower. The bridge removed one of the worst traffic bottlenecks on the roads between Paris and the Mediterranean.

The viaduct lies in the communes of Millau and Creissels in the Aveyron department. It was needed because the new motorway from Clermont-Ferrand to Montpellier, a second north–south route alongside the Rhône valley motorway, had to bypass Millau and cross the Tarn valley. Encyclopaedia Universalis notes that it completed a continuous motorway link between Clermont-Ferrand and Béziers, joining the Lévézou plateau to the Causse du Larzac, and removed one of the main traffic black spots between Paris and the Mediterranean.

The deck is 2,460 m long (the distance between the abutments) and 32.05 m wide, about 300 m above the Tarn. It is a toll bridge, operated by Eiffage. In 2017 it received France's '20th-century heritage' label.

Count the white masts on the bridge. There are seven!

Thin cables go down from each mast like the strings of a harp. They help hold the road up.

The Millau Viaduct is a cable-stayed bridge. Each of its seven pylons has 11 pairs of cables, called stays, fanning down to the deck and holding it up. Between the piers are eight spans, and the six in the middle are each 342 meters long.

The deck is 32 meters wide. Screens that block the wind let cars and trucks keep crossing even in very strong winds. In the photo, you can count all seven pylons standing above the deck, with the cables fanning out from each one.

The viaduct is a multi-span cable-stayed bridge whose piers have a tuning-fork profile. Its eight spans include six main spans of 342 m; each pylon carries eleven pairs of stays connected to the steel deck, which is topped by a road surface.

Universalis reports that wind screens let vehicles keep crossing in winds of around 200 km/h and that the structure itself is designed to withstand winds of 250 km/h. The site, Buonomo wrote, lies at about 700 m altitude in a valley 2,400 m wide, open to all the winds, with regular winter snow on the surrounding causses.

Lots of people come just to look at the bridge.

In the photo, a village with red roofs sits below it. Green fields stretch across the valley.

Besides carrying traffic, the Millau Viaduct has become a sight that many visitors come to see. Encyclopaedia Universalis says it fits remarkably well into the landscape of the Tarn valley, which is very wide at this point.

In the photo, the red-tiled roofs of Creissels, a village on one side of the valley, are in front. The deck stretches across the whole picture, and on the left a thin layer of low cloud hangs along the hillside.

Universalis describes the viaduct as fitting remarkably into the Tarn valley, which is very wide here compared with the gorges about 50 km upstream, and as a notable tourist attraction; Buonomo wrote that its silhouette gave Millau a new attraction. Eiffage operates it as a toll bridge under its concession.

The photo, with Creissels in the foreground, shows the full deck with all seven pylons and their stays, the farmland of the valley floor, the village's roofs in the foreground and low cloud along the hills on the left.