The Millau Viaduct, by engineer Michel Virlogeux and architect Norman Foster, is a contemporary proof of how an infrastructure structure can produce a slender elegance from pure engineering necessity. The bridge crosses the Tarn valley in southern France; so deep a valley that the bridge deck often stands above the clouds — its tallest mast is higher than the Eiffel Tower.

The problem is to cross so deep a valley slender and light, with few supports. The solution is the cable-stayed system. The deck does not merely rest on the seven slender concrete piers rising from the valley floor; it is hung from above by steel cables fanning out from a mast atop each pier. The span between piers thus grows, the piers thin, and the bridge reads not as a heavy mass but as a taut net of wire and steel — almost immaterial. The piers taper as they rise and split in two near the top to increase flexibility, to accommodate movements of temperature and wind.

The most critical design problem is the wind: at this height the deck could vibrate and twist like a wing in a storm. The solution is to give the steel deck an aerodynamic, fluid section like an aircraft wing; this profile, shaped by wind-tunnel testing, lets the wind pass over the bridge without shaking it. Millau unites Maillart's tradition of 'structural art' with the computational power of the digital age: the form is still the direct expression of force, but now of a force refined by computer and wind tunnel.