Cize-Bolozon viaduct

The Cize-Bolozon viaduct is a double-deck structure that bridges the Ain gorge with a length of 273 meters, carrying rail traffic above and road traffic below. The two decks sit at different heights, allowing both transportation modes to cross the steep ravine simultaneously.

The viaduct was built in 1875 to solve a regional transportation challenge in this mountainous area. It was destroyed during World War II but was reconstructed and reopened in 1950 to restore connections between the towns.

The structure serves as a vital connection for local communities on either side of the gorge, shaping how people travel through the region. Its role as a working transport link makes it a familiar part of daily life for those who live nearby.

The viaduct can be crossed on foot or by car, with pathways clearly marked for pedestrians on the road deck. Visiting on quieter days makes it easier to walk across and enjoy the view over the gorge without heavy traffic.

This is the only viaduct in France designed to carry both rail and road traffic on separate decks in this exact configuration. The engineering approach of stacking two different transport systems vertically is an unusual solution born from the need to cross the gorge without taking up more land.

Location: Bolozon

Location: Corveissiat

Inception: 1875

Floors above the ground: 2

Height: 73 m

Length: 273 m

Part of: Ligne du Haut-Bugey

GPS coordinates: 46.21554,5.45123

Latest update: December 10, 2025 20:00