Violette viaduct, Road bridge in Grenier-Montgon, Haute-Loire, France

Violette viaduct is a road bridge made of steel reinforced concrete that spans 564 meters across a valley and rises 75 meters above the ground. The structure carries traffic over terrain that would otherwise require a lengthy detour through the landscape.

The viaduct opened in spring 1991, carrying the A75 motorway over the Violette valley in Grenier-Montgon. It was built to let the A75 cross from Haute-Loire into Cantal, replacing the detour through the valley below. The 564-metre structure stands on piers up to 75 metres high.

The viaduct carries the A75 between the Haute-Loire and Cantal departments, on the Grenier-Montgon commune east of the Montgon hamlet. Its name comes from the Violette valley it crosses, 75 metres below the deck. Drivers pass it on the motorway; the four pale grey concrete piers are the visible marker of the crossing.

The viaduct carries the A75 between the Haute-Loire and Cantal departments, in the commune of Grenier-Montgon east of the hamlet of Montgon. Drivers cross it in seconds, so plan to view it from outside the roadway rather than slowing on the carriageway. The deck stands 75 m above the Violette valley floor.

The viaduct uses steel reinforced concrete technology that allows it to span large distances with fewer support pillars than traditional designs. This engineering approach reduces visual obstruction while maintaining structural strength across the valley.