As part of a road decongestion programme in Mauritius, Bouygues Travaux Publics is involved in the Pont Fer project, including a colossal viaduct erected between two cliffs in the north-west of the island. The viaduct joining the A1 and M1 motorways will be a real revolution, facilitating links between the north and south of the island and connecting the valley's inhabitants.

Its construction is extremely complex, as it is 330 metres long and lies 100 metres above the Grande Rivière Nord-Ouest, while the spans of its deck feature an imbalanced number of segments: a highly unusual occurrence in an engineering structure. To achieve this, the outer spans are being constructed using temporary stay cables. These are used to support the segments that cannot be held in place by the final stay cables, until they are finally joined to the abutment piers.