Widening the A75 North: the huge multi-task roadworks have been completed

It has taken almost four years for the APRR teams to widen a 10.5 km section of the A75 motorway into 2 x 3 lanes, near Clermont-Ferrand in the Auvergne region. The least that can be said is that there were multiple difficulties and numerous surprises for these motorway roadworks, which by-pass the Clermont-Ferrand conurbation to the east and serves the south of France towards Montpellier. For the new constructions had to be integrated with existing ones in a very special geological, historical and agricultural context, with the traffic continuing to flow and major archaeological discoveries having to be taken into consideration.

However, drivers can now travel along the A75 on three lanes, from the junction with the A71 (Clermont-Orléans) to the La Jonchère interchange (no. 5) located on the "Méridienne" to the south-east of Clermont-Ferrand. As it is already part of the APRR concession, this section is toll-free. The actual investment represented approximately €170m.
This operation was overseen and funded entirely by APRR. Of course, there were challenges. But APRR and the 245 companies that worked on this demanding and difficult site were able to overcome them. To mention just a few: redesigning the slip roads of the interchanges, demolishing and immediately rebuilding engineering structures in record time, e.g. just a weekend for the largest one (1500 tonnes), as well as talking to, and interacting with, local stakeholders while at the same time respecting the landscape and countryside being worked on. In some stages of the roadworks, up to 400 construction professionals had to be on site at the same time. Eiffage group was involved in building bridges and motorway intersections.

Over 100,000 trees planted
Though much of the roadworks were in an urban area, at its southern end the motorway crosses through rural countryside. Here it is often hidden with cuttings or on hillsides, and over time has blended in well with the local topography and landscape. But more importantly, the motorway is part of a special site classified as a UNESCO World Heritage Site: the Chaîne des Puys and the Limagne Fault.
This meant that the APRR teams had to create landscape developments for the whole section concerned by the roadworks. Everything was done so that adding in a third lane only required a limited amount of new land, the aim being to preserve the way the infrastructure blends in with the landscape. So APRR wanted to replant a large number of local tree species in order to maintain the greenery that is typical of the Clermont urban area: in total, 700 trees, 20,000 saplings* and 82,000 shrubs were planted or are well on the way to being planted along the whole route.
*For a future forest of tall trees

Standing stones alongside the motorway
APRR also funded various archaeological excavations as required by the French government, which were managed and dug by the INRAP (France's national institute for preventive archaeological research). These investigations led to major discoveries in Veyre-Monton: for the first time in the Auvergne, i.e. in the central region of France, lines of standing stones were uncovered in the earth! The 1.6 hectare dig revealed around thirty monoliths, between 1 m and 1.60 m tall. These standing stones form a line that is more or less in a straight line and continuous. Around the edges are other large blocks forming a horseshoe shape, like a Stonehenge in the Auvergne. The digs also brought to light a human-shaped statue representing a female deity. Currently this stone statue is the only known example in the Auvergne. Though very rare in France as a whole, they are found mainly in the South.
Finally, a monumental tomb was excavated. A rectangular burial mound, 14 m long and 6.5 m wide, was built around a central tomb. This tomb contained the remains of a large man. His body was protected by a wooden container, which has since rotted away, surrounded and supported by stone blocks. Some of these stone blocks could correspond to standing stones that were moved or deliberately broken. Despite the proximity of the Gallic sites of Gergovia and Corent, and the figures of Obelix and Asterix in the popular imagery, these artefacts are much more ancient than the Gallic period! The precise chronology of the occupations is still to be established, particularly via further analyses to be carried out by radiocarbon (carbon 14) testing of the skeleton and the rare animal remains.

Innovative agricultural compensation schemes
In partnership with local authorities and the agricultural industry, APRR wanted to do
more than just contribute financially for the land affected by widening of the motorway. The concessions company therefore launched a call for innovative proposals for collective compensation. The idea was to bring out initiatives with a strong added value for agriculture, livestock farming, the local economic fabric and employment. In addition, a grant of €250,000 was given by APRR to fund these initiatives.
Of twelve proposals submitted, four projects rooted in the heart of the Clermont region were retained:

• Development of a training orchard,
• Creation of a meat cutting facility for the livestock farmers of the Dôme Sancy Élevage,
• Promotion of Billom pink garlic,
• Opening of a supply hub for local organic products for wholesale to the public of the Clermont-Ferrand urban area.

Depending on the project, funding of between 40 and 80% was granted. An agreement was signed for each project between APRR and the selected entities. A steering committee would then supervise running of the project. This is an entirely new practice in the Puy-de-Dôme department.

As well as its motorway design role, with these exceptional projects APRR is confirming its role as a comprehensive regional developer, respecting all of the diversity, complexity and special features of the regions.

© Picture : Philippe Busser- XXI Communication