Viaduc de Gennevilliers, Highway bridge in Argenteuil and Gennevilliers, France.

The Viaduc de Gennevilliers is a motorway bridge spanning just under a kilometer across the Seine, connecting Argenteuil and Gennevilliers. The structure was built as a dual-bridge system with adjustable center barriers that allow flexible traffic lane distribution.

The first viaduct opened in 1976, built between 1974 and 1976 by Campenon Bernard to a design by Jacques Mathivat, advised on architecture by Alain Spielmann; at its inauguration it was France's largest prestressed concrete bridge built by cantilever construction. A parallel viaduct was added between 1990 and 1992 by Spie Batignolles. On 15 May 2018 a retaining wall at the north abutment collapsed, closing the Paris-bound lanes; all four lanes reopened on 19 March 2019.

The bridge functions as a vital transport link for the north Paris area, shaping how thousands of commuters cross the Seine daily. It has become a necessary part of local routines for people moving between these two communities.

The A15 viaduct carries four lanes plus a hard shoulder in each direction, one deck per direction, with the second deck east of the first. Drivers heading toward Paris on the right bank of the Seine pass above the port basin no. 5 and the Seine entrance channel. The structure links to the A86 interchange at its southern end and to the D 311 at its northern end.

The bridge uses a system of adjustable center barriers that shift lanes between two and three in each direction depending on time of day and traffic needs. This flexible design was created to handle the vastly different rush-hour volumes.