Viaduc de Nantua, Highway bridge in Nantua, France
The Viaduc de Nantua is a highway bridge in eastern France that carries traffic across a deep valley. The structure rests on ten concrete pillars that support the roadway spanning more than a kilometer across the landscape.
The first deck opened in 1985, carrying both directions of the A40 on a single carriageway. A second, separate viaduct entered service in 1996, giving the motorway two times two lanes across the Nantua valley at the exit of the Chamoise tunnel.
The viaduct takes its name from Nantua, the town whose valley it crosses at the north-east exit of the Chamoise tunnel. It is one of a chain of viaducts on the A40 toward Annemasse: the Neyrolles viaduct (782 m) follows immediately, then Glacières, Sylans, Charix, Lalleyriat and Frébuge.
When crossing, expect regular traffic flow on this motorway section. Keep in mind that the viaduct emerges directly from a tunnel, so adjust your visibility and driving awareness accordingly.
The viaduct is actually two parallel structures, one per direction of traffic, each carried by about ten piers. The tallest piers rise 77 metres, roughly the height of a thirty-storey building, which is also where drivers emerge from the Chamoise tunnel. The piers were cast in place with climbing formwork, and their foundations were poured 14 to 21 metres deep.
The community of curious travelers
AroundUs brings together thousands of curated places, local tips, and hidden gems, enriched daily by 92,893 contributors worldwide.
