A79: a construction site that is going full steam ahead

A79: a construction site that is going full steam ahead

The work to widen the RN79 and bring it up to motorway standard is in full swing. After signing the contract in March 2020 and obtaining the environmental permits required to start work in September 2020, most of the preparatory work was carried out in the second half of 2020. After a rapid ramp-up in the first half of 2021, the site has now reached its peak with all the trades working together on site, mobilizing over 1,300 people.

This summer, the project will come to a head with the completion of earthworks, the release of subgrade and the ramping up of linear activities: pavements, drainage and equipment.

However, several challenges must be met in the short term, in particular adaptations to the phasing around the last archaeological excavations, land releases that will remain open until the end of September, management of coactivity during the peak of pavement and equipment work, and an early start to operating equipment work with the installation of the first free-flow gantries... On the fixed operating facilities side (Service Area and Halt buildings), after the appointment of contractors in December 2020, work began in April.

It is on the site of the Deux-Chaises full-lane toll plaza that the stakes are the highest in terms of general planning and, more specifically, the planning of the tests and dry runs required for the start-up of the free-flow toll collection system. On the civil engineering side, the majority of the viaducts, for which the installation of the frameworks began in January, should be completed by the end of the year after only 11 months of work. The upgrading of existing structures began in March and more than a third of the overpasses have been brought up to standard and put back into circulation.

Lastly, 185,000 t of asphalt gravel and concrete have been applied to the pavements and a total of 25 km has been opened to traffic. By the end of August, half of the asphalt should have been applied, representing nearly 450,000 t. 

Photo credit: Hervé Piraud