Millau Viaduct

Designed with engineer Michel Virlogeux, the 2.46km-long cable-stayed bridge has the highest elevated roadway in the world. Supported on seven concrete piers of varying height, its deck is 270m above the River Tarn.

Each of its sections spans 342 metres and its columns range in height from 75 metres to 245 metres, with the masts rising a further 90 metres above the road deck.

A three per cent slope from south to north encourages drainage, while a gentle curve as the bridge approaches the northern plateau helps wind resistance. But both these factors work aesthetically too, accentuating the sense that the structure is tailored precisely to a specific site.

This marriage of the functional and aesthetic continues in the tapered concrete piers, which bifurcate towards the top to cope better with thermal movement in the steel deck (trapezoidal in section), while making the supports seem more slender.