Millau Viaduct mid-1998. After undergoing wind tunnel tests, the shape of the road deck was altered, and detailed corrections were made to the design of the pylons. When the details were eventually finalised, the whole design was approved in late 1998. Once the Ministry of Public Works had taken the decision to offer the construction and operation of the viaduct as a grant of contract, an international call for tenders was issued in 1999. Five consortia tendered: Piers were built with Lafarge high performance cement. The pylons of the Millau Viaduct, which are the tallest elements (the tallest pylon – ) were
Millau Viaduct and structural engineer Dr Michel Virlogeux. He worked with the Dutch engineering firm ARCADIS, responsible for the structural engineering of the bridge. The 'high solution' required the construction of a viaduct. From 1991 to 1993, the structures division of Sétra, directed by Michel Virlogeux, carried out preliminary studies, and examined the feasibility of a single structure spanning the valley. Taking into account technical, architectural, and financial issues, the Administration of Roads opened the question for competition among structural engineers and architects to widen the search for realistic designs. By July 1993, seventeen structural engineers and thirty-eight architects applied as candidates