At 3,356 metres in length, this structure consisting of two concrete access viaducts and a cable-stayed steel deck, remains the longest bridge in France. To reinforce the structure of the girders of the south and north viaducts, Bouygues Travaux Publics optimised its methods by designing floating pontoons which, hoisted under the spans, served as working platforms. These barges were used to transport equipment, materials and waste. The structural reinforcement of the girders was carried out using an isostatic solution of additional external prestressing. The application of strips of carbon fibre composite material locally reinforced the rebar reinforcement. Finished in 2013, the work on the south viaduct was complemented in 2020 with new operations on the north viaduct: installation of a permanent intrados footbridge, repair of the beams, struts and underside of the slabs, application of a coating on 22 spans, protecting the concrete from sea spray and sea air, thus limiting corrosion of the reinforcements.