A41 Motorway

Location
France, Villy-le-Pelloux
Delivery
December 2008
Client
ADELAC
Contractor
Bouygues Travaux Publics, Bouygues Bâtiment Grand-Ouest, Bouygues Bâtiment Sud-Est, Losinger Marazzi

Design and construction of a mountain motorway

Despite its short length (18.8 kilometres), this 2x2 lane motorway was a highly complex project, presenting both technical and operational challenges.

Its route between Annecy and Geneva passes through steep valleys and mountain ranges, requiring the excavation of a 3.1-kilometre twin-tube tunnel under Mont Sion.

The project also includes four viaducts (including the 360-metre-long Usses viaduct), a 290-metre cut-and-cover tunnel, 25 standard engineering structures, and an interchange with the A40 and A401 at Saint-Julien-en-Genevois.

Un long viaduc moderne traverse une vallée luxuriante aux couleurs automnales, avec des forêts aux teintes orangers et vertes. En arrière-plan, on distingue des montagnes bleutées sous un ciel clair.

4,3 M
m³ of excavated material
800 000
m³ of blasting
2,2 M
m³ of fill
150
earthmoving machines

Sustainable mobility at the heart of Alpine regions

Completing the construction within a particularly tight timeframe of 31 months represented another major challenge for this project. This was achieved through the implementation of four autonomous sub-projects, a trade-based organisational structure, and optimised management of excavated materials.

Environmental measures—including landscape integration, protection of flora and fauna, and 3,000 metres of noise barriers—were also put in place. Now linking Annecy and Geneva in just 30 minutes (compared to 1 hour and 15 minutes previously), this infrastructure greatly improves daily life for the residents of Haute-Savoie and all the communities along the Alpine corridor between Grenoble and Geneva.