Viaduc de la Côtière, Highway bridge in La Boisse and Beynost, France

The viaduc de la Côtière is a 1,210-metre-long, 30-metre-wide concrete viaduct carrying the A432 motorway between the A46 and A42, straddling Beynost and La Boisse in the Ain. Its flat deck has a red-edged underside and a curved grey metal railing, and rests on tall rectangular concrete piers that taper slightly downward, with trees and grass below.

Built from 2008 to 2011, the viaduct carries the A432 motorway, which links the A46 and A42. The Les Échets–La Boisse motorway section opened in early 2011. It stands immediately beside and parallel to an earlier viaduct of the same name, built in 1991 for a high-speed railway line.

The A432 viaduct runs parallel to an earlier railway viaduct of the same name, built in 1991 for the high-speed line. The two structures stand side by side between Beynost and La Boisse, so drivers on the motorway see the railway bridge immediately alongside. The name Côtière refers to the ridge the crossings traverse.

The viaduct carries the A432 motorway between the A46 and A42; there is no pedestrian or cycle access on the deck. It stands beside the 1991 railway viaduct of the same name, so the two structures can be seen together from the roads below, near Beynost and La Boisse.

The structure was built alongside a separate railway bridge that also crosses this route. This parallel arrangement shows how highway and rail infrastructure projects are planned side by side in modern times.