Millau Viaduct, Millau, France

gkat_014.pdf44° 4′ 46″ N, 3° 1′ 20″ E

The World’s Highest Road Bridge

The Millau Viaduct is over 2 kilometers long and stands 270 meters above the River Tarn in southwestern France. It is the highest road bridge in the world—its highest pylon is 343 meters tall (slightly taller than the Eiffel Tower, Chapter 18, and slightly shorter than the Empire State Building). And it’s striking to see, because, despite its immense size, it seems almost fragile.

The viaduct is part of an important autoroute link that allows Parisiens fleeing the city in the summer to arrive at the warm beaches of southern France without having to descend into the Tarn river valley at Millau and climb back out again. Before the viaduct was built, Millau was a major point of congestion, as drivers had to leave the autoroute and drive along local roads. The cost of the bridge’s construction was 400 million euros, but it’s a small price to pay for not having thousands of overheated, frustrated Parisiens race through your town in July and August.

As well as being a piece of high-tech construction, the viaduct itself is full of high-tech monitoring equipment. It contains a large Ethernet network that links together equipment in each of the seven pylons. The equipment includes accelerometers (which are used to measure any oscillation of the viaduct to the nearest millimeter), ...

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