The Croix Rousse Tunnel opened in the 1950s. This 1,750 m long tunnel is located in the heart of Lyon between the Rhône and the Saône Rivers. Currently, around 50,000 vehicles pass through the tunnel every day.
The need to upgrade the tunnel in line with road safety requirements led the project owner to launch a call for tender for a design-build contract involving:
- digging a second tube to provide safety access to the car tunnel, while serving as a route for cyclists, pedestrians and public transport. This required strong architectural features to minimize the road aspect and maximize the aesthetic experience,
- denovating the stonework of the existing tunnel to create a new lining and replace the cross-ventilation system with longitudinal ventilation and heavy-duty extraction fans,
- creating 11 access points between the tubes,
- completely overhauling the five ventilation plants located on the top of the Croix Rousse hill,
- updating the entrances,
- replacing all the equipment,
- introducing a hypervisor surveillance system for all tunnels in Lyon.
