A TOUCH OF FRANCE – World’s tallest bridge spans ancient pilgrimage routes in France

by P. Jodidio, Switzerland


High above the banks of the Tarn River in the Aveyron region of France, a singular bridge called the Millau Viaduct, designed by the French engineer Michel Virlogeux and the British architect Norman Foster, carries automobile traffic north and south. In the lands below, the history of France from the Roman or even Barbarian occupation to the pilgrims of the Way of Saint James has played out, leaving monuments as famous as the Abbey Church of Saint-Foy in Conques along the route. Today, the natural beauty of the region, but also products such as the famous cheese of Roquefort-sur-Soulzon, are highlighted by one of the most remarkable works of civil engineering in the world.

Medicographia. 2015;37:468-477 (see French abstract on page 479)

Those who know the history and geography of France will be familiar with the Aveyron. Though it remains one of the least densely populated departments of France, this region, located between Toulouse, Clermont-Ferrand, and Montpellier, retains a natural beauty and a presence of the past that set it apart, even in the rich tapestry of French culture. Nearby sites of interest include the canyon of the Tarn River (Gorges du Tarn), which is 53 kilometers long and between 400 and 600 meters deep. The Aveyron is also home to the town of Roquefort-sur-Soulzon, famous for its eponymous cheese for which the village was given a monopoly in 1411 by King Charles VI. The authenticity of the cheese was rather unexpectedly confirmed in 1961 by the Tribunal de Grande Instance in Millau, which declared that only cheese ripened in the Mont Combalou caves at Roquefort-sur-Soulzon could carry the name Roquefort. Local brands such as Roquefort Papillon and Roquefort Société produce nearly 20 000 tons of the cheese each year, attracting a good number of tourists in the process.

The town of Millau and eponymous viaduct. © Karl Thomas/Robert harding World Imagery/Corbis.

Millau and the Aveyron: a historical nexus

Millau is also near to the Abbatiale Sainte-Foy de Conques, the Abbey Church of Sainte-Foy, a masterpiece of the Romanesque period. The presence of this monument, begun between 1050 and 1065 and completed in 1120, points to another long tradition of the Aveyron, which is crossed by the Puy-en-Velay pilgrimage route of Santiago da Compostela, or the Way of Saint James. One of the four main pilgrimage routes in France, the Puy-en-Velay path leads from the valley of the Rhone toward Spain. Together with numerous other monuments along the ancient route, the Abbey Church became part of the UNESCO World Heritage List in 1998. The UNESCO listing is justified in terms that relate specifically to the Abbatiale Sainte-Foy de Conques:

Criterion (ii): The Pilgrimage Route of Santiago de Compostela played a key role in religious and cultural exchange and development during the later Middle Ages, and this is admirably illustrated by the carefully selected monuments on the routes followed by pilgrims in France.
Criterion (iv): The spiritual and physical needs of pilgrims travelling to Santiago de Compostela were met by the development of a number of specialized types of edifice, many of which originated or were further developed on the French sections.1

Meals on wheels? Roquefort “wheels” maturing
in the cellars at Roquefort-sur-Soulzon.
© Christian GUY/imageBROKER/Corbis.

Sainte-Foy Benedictine Abbey (1035-1060) at Conques, in the Aveyron. © akg-images/Erich Lessing.

UNESCO specifically identifies as “pilgrimage churches” Sainte-Foy at Conques, Saint-Sernin at Toulouse, and the Cathedral of Santiago de Compostela itself “because of their large transepts and apsidal chapels ranged round a spacious ambulatory, designed to meet the liturgical needs of pilgrims.”

The Abbey at Conques was actually founded in 819 about when relics of St James were discovered in Compostela. Seeing that pilgrims headed for Spain were stopping at Agen, where relics of Sainte Foy were kept, the Benedictine monks of Conques conspired to steal her mortal remains. Kept in a golden reliquary statue in Conques, these remains sufficed to shift the pilgrimage route from Agen and to duly enrich Conques, whose new-found wealth was used to build the Abbey Church. The 80-centimeter–high reliquary, made of gold, silver gilt, gems, and cameos over a wooden core, is still conserved in the Treasury of Sainte- Foy, where it continues to attract tourists and pilgrims.

A more modern pilgrimage route of sorts, the A75 highway, also crosses through the Aveyron running 340 kilometers north from the area of Béziers, Narbonne, and Montpellier across the Massif Central to Clermont-Ferrand. The Massif Central is a large mountainous and volcanic (more than 450 extinct volcanoes) plateau region in south-central France, which extends over close to 15% of the country. The motorway passes close to the town of Millau near the confluence of the Tarn and Dourbie Rivers. As is often the case in France, profound historical reasons influence the course of roads. As it happens, a Roman road also led north from the Languedoc region, crossing the Tarn. Settled on the left bank of the Tarn in the 2nd or 1st century BC, Millau was a place of trade and a victim of numerous invasions, by barbarians and others, which led the townspeople to resettle on the opposite bank of the river in the 4th or 5th century AD. By the 9th century, Millau was already known for the production of lambskin gloves, a tradition that has continued into modern times with the leather and leatherwear industry.

Majesty of Saint Foy (“Holy Faith”)
statue reliquary in gold and precious stones
(10th century), formerly in the Conques
Abbey, now in the neighboring Musée
du Docteur Joseph Fau. Courtesy of the
Office de Tourisme Conques-Marcillac.
© Robert Magorien.

The layering of history seen in Millau finds an intriguing echo in the remains of a medieval bridge, of which only two sandstone and volcanic tuff stone pillars remain, one topped by a more modern mill. Reference is found to a bridge at this location in 1156 when the Count of Barcelona, then Millau’s ruler, granted free passage to monks from the nearby Cistercian Abbey of Sylvanès. Millau was then successively ruled by the King of Aragon in the 12th century, becoming French in 1271 only to fall under English rule during the Hundred Years War in 1361. The town and its region again became French in 1476. The medieval bridge, a 17-span, 218-meter long witness to the long history of trade and movement through the area, fell to flooding in 1758 and was never rebuilt as such. With a population of about 22 000 persons, Millau is set in a predominantly agricultural and rural area, characterized by numerous gorges and ravines.

Leather-craft and glove-maker store in Millau, France’s capital of tanneries.
© akg-images/Catherine Bibollet.

More specifically, the town is located astride the southern part of the Massif Central near the Grands Causses Regional Park. The Grands Causses are a series of high limestone plateaus, valleys, and gorges.

The Millau Viaduct: a joint architectural-engineering project

It is in this unusual geographic setting that it was decided to build one of the most spectacular bridges in the world, the Millau Viaduct, which was completed in 2004. Intended to alleviate excessive holiday traffic heading south or north, four potential routes for the A75 Highway linking the Causse Rouge to the north and the Causse du Larzac to the south were carefully studied. In 1989, the so-called “median” route located a few kilometers to the west of Millau was chosen. From the outset, this route promised to be one of superlatives because of the depth of the Tarn River valley and the 2.46-kilometer span required to travel from one plateau to the other. The completed structure is the highest road bridge deck in Europe, passing 270 meters above the Tarn River.

Group with British architect Norman Foster (gray jacket, center). Courtesy of Eiffage and
Foster+Partners, London, UK.

Between 1993 and 1994, the French government consulted a total of seven architects and eight structural engineers. In 1995 and 1996, five groups associating architects and structural engineers prepared a study defining the issues concerned. In 1996, teamed with the French engineering companies SOGELERG (Michel Virlogeux), EEG (Europe Etudes Gecti), and SERF, Norman Foster won a limited competition against French architects to build a 2.5-kilometer viaduct. Though it is not highly unusual, it was somewhat unexpected that architects played such a prominent role in this process. Many significant bridges have been designed purely by engineers, with architects perhaps taking an increasing role in recent years. Such architects as Zaha Hadid (Sheikh Zayed Bridge, Abu Dhabi, UAE, 1997-2010) or Ben van Berkel (Erasmus Bridge, Rotterdam, The Netherlands, 1996) have successfully delved into this domain, while others such as the architect- engineer Santiago Calatrava have built many bridges. Even as he worked on the Millau Viaduct, Norman Foster was designing and building the very visible Millennium Bridge (London, UK, 1996–2002), a pedestrian span that links Saint Paul’s Cathedral on the north bank of the Thames to Tate Modern in Southwark.

Millau: new viaduct and old bridge. © Murat Taner/Corbis.

Norman Foster, born in Manchester in 1935, is one of the best-known figures in the world of contemporary architecture. He received the RIBA Gold Medal for Architecture in 1983. He was knighted in 1990 and was honored with a Life Peerage in 1999. The American Institute of Architects granted him its Gold Medal for Architecture in 1994, and he received the Pritzker Prize in 1999. Aside from bridges, Foster is no stranger to other technical structures that are usually designed by engineers. His Torre de Collserola communications tower (Barcelona, Spain, 1992) is 288 meters high. Foster is proud of the fact that a more conventional design for a tower of this height would have required a main support more than six times broader than the 4.5-meter-diameter hollow slip-formed reinforced concrete shaft that reduces to just 300 mm to hold a radio mast. In the context of the Millau Viaduct, in a discussion with the author of this article, he stated:

It is why some things, which appear to be very simple, look better than others, whether it be aircraft or bridges. You don’t have to be an architect to have an eye, and I know lots of architects who don’t have an eye. When you see a bridge that really sings, then you can be sure that that engineer had an eye. When you see one aircraft which is more remarkable than another, the same is true. They are all obeying the laws of nature. There are a whole series of visual options that permit one to achieve an optimal engineering solution, whether it is in designing a building, a bridge, or an aircraft. You are making a choice. You are using an eye.2

In the case of the Millau Viaduct, Foster had a number of associates who were engineers. He explains:

Bridges are often considered to belong to the realm of the engineer rather than that of the architect. But the architecture of infrastructure has a powerful impact on the environment and the Millau Viaduct, designed in close collaboration with structural engineers, illustrates how the architect can play an integral role in the design of bridges. It follows the Millennium Bridge over the River Thames in expressing a fascination with the relationships between function, technology, and aesthetics in a graceful structural form.

The 565-meter-long Garabit Viaduct, a railway arch bridge, spanning the river Truyère, constructed between 1882 and 1884 by
Gustave Eiffel, father of the Eiffel Tower. The successor of his construction company, Eiffage, built the Millau Viaduct (2004).
© Günter Lenz/imageBROKER/Corbis.

Despite the very large scale of this project, it achieves a lightness and elegance that does not damage the natural setting and projects an image of modern automobile travel. The coarchitects for the project were Chapelet-Defol-Mousseigne, and the consultants were EEG, SOGELERG, SERF, Agence TER, and Michel Virlogeux. Michel Virlogeux, born in 1946 in the Sarthe region of France, went to work for the French Highway Administration (SETRA) in 1974. As head of the Bridge Division, he designed more than 100 bridges. He worked on other significant spans, such as the Normandy Bridge (Honfleur, France, 1994), which at the time was the longest cablestayed bridge in the world. He left SETRA in 1995 to become a consultant. It is in this capacity that he worked on the Vasco da Gama Bridge (Lisbon, 1997) and on the Millau Viaduct. Although originally overshadowed by the presence of Norman Foster in the communications surrounding the Millau Viaduct, Virlogeux subsequently was understood to have played a leading role in the design. He continues to give credit to the British architect, however. He states,

I am able to see what kind of structure is fitting to the landscape, and what is technically suited to the conditions and constraints of the location. I’m able to develop the global proportions. But I’m not able to do the detailed shaping, and that’s not a minor role. From the global idea, you can form the detailed shape, so that it expresses the flow of forces and can enhance the structural concept. This is something that, personally, I cannot do.3

In June 2000, a contest for the construction contract of the Millau Viaduct was launched, with four invited consortia. In March 2001, Eiffage established a subsidiary called Compagnie Eiffage du Viaduc de Millau (CEVM) and was declared winner of the contest with a steel-deck proposal and awarded the prime contract in August of the same year. This 75- year concession for the financing, design, construction, operation, and maintenance of the Viaduct was confirmed by a French government decree published in the Journal Officiel on October 10, 2001. The concession contract stipulates a “useful project life” for the Viaduct of 120 years. This system allowed the bridge to be built entirely with private funding.

With columns varying in height between 75 and 245 meters, the Viaduct is a multispan cable-stayed design with sections each of no less than 350 meters in length. Making its design and construction even more complex, the Viaduct is curved and has a constant upward slope from north to south of just over 3%. The curve was added to avoid the floating sensation that drivers might have felt in a completely straight de- sign and also to allow them better visibility. Further difficulty accrued from the potential of high winds, especially given the distance from the road deck to the bottom of the gorge. Wind tunnel tests were conducted at the CSTB in Nantes, taking into account wind effects and potential air turbulence, which resulted in relatively slight design changes. The significance of these studies is underlined by the fact that the wind accounted for 25% of total forces and loads acting on the Millau Viaduct during construction.4 Even the construction of the Viaduct was innovative. Rather than cantilevering the road deck outward in small sections from each of the seven pylons as would have been expected, the deck was built on flat sites on either side of the bridge in two large sections. Hydraulic jacks on the tops of the piers were synchronized to move the entire deck out in increments of 600 mm until both sides met over the river. This method required the construction of temporary intermediate piers to avoid buckling of the deck.

Opened in December 2004 after three years of construction, the Viaduct cost approximately 400 million euros to build, and created a certain controversy because it is the tallest bridge in the world, with one mast reaching a height of 336.4 meters (P2 pylon). In this instance, the P2 pylon is 245-meters high and the mast rises a further 87 meters above the deck. Such statistics raised local concern that the Viaduct threatened to dwarf the features of the countryside, and associations such as the World Wildlife Fund actively opposed the project. In fact, the controversy reached the highest levels of the French government. Before construction, Valéry Giscard d’Estaing, the former President of France, went so far as to write to his successor Jacques Chirac:

This project must elicit the most serious reservations, which is why I ask you to reexamine this question at your earliest convenience… The project envisaged for Millau belongs to the family of cable-stayed bridges, often built near the entries to ports or in the mouths of rivers… In designing a bridge that spans a valley at such a great height, it is necessary to obtain a less opaque profile, which is less oppressive for the surrounding countryside.5

Today’s pilgrims on ancient routes: the French Path (Camino Francés) of the way to Santiago de Compostela.
© akg-images/Universal Images (Lissac)/GODONG.

The project was bound to elicit a certain amount of hostility toward Norman Foster among some, but it may be suspected that in this instance it was related to a lingering reticence about the virtues of contemporary architecture and perhaps also to the fact that he was English. In fact, his work was the result of the solution favored by the French Roads Department (AIOA) and the engineers associated with the project, SOGELERG, FFG, and SERF. The influential public works magazine Le Moniteur went so far as to openly take position in this controversy in a revealing way:

Far be it from us to deny the talent usually displayed by the winner of this competition, the Englishman Sir Norman Foster. Far be it from us, in the midst of the construction of the European Community, to argue that preference should be given to French candidates, even if the architectural profession in this country is in a state of severe depression. Couldn’t it be imagined, though, that French architects might one day receive such commissions in Italy, England, or Spain?6

Aerodynamic side screens to shelter drivers on the Millau Viaduct from the frequent very high winds. © Jean-Philippe Arles/Reuters.

As it happens, the completed Millau Viaduct in no substantive way disfigures the landscape more than might have a 17-arch medieval stone bridge, for example. Rather, the involvement of Norman Foster and the will to make the Viaduct fit into its grand natural setting assured a degree of discretion and elegance that is rare in contemporary architecture and engineering. Norman Foster stated in 2011, “We wanted the piers to look as if they had barely alighted on the landscape, light and delicate—like butterflies’ legs.”

A winner of the prestigious 2006 IABSE (International Association for Bridge and Structural Engineering) Outstanding Structure Award, the bridge is indeed a remarkable combination of very large elements and outstanding lightness. The IABSE citation emphasizes the fact that:

Piers P2 (height 245 m) and P3 (height 223 m) are the two highest piers ever built in the world. From their base to 90 meters below the deck, the piers rise as a single hollow shaft, then they are divided into two separate parallel shafts, which are each pre-stressed vertically by eight cables.7

Much as had been the case with Ieoh Ming Pei’s Louvre Pyramid, completed in 1989 after bitter, politically-oriented controversy, the completed Millau Viaduct has since imposed itself not only as a local tourist attraction, but as one of the most remarkable technical achievements in France in the late 20th century; each year, a million people visit the viewing platform of the Viaduct.

Local tourist offices claim that what the Eiffel Tower is to Paris, the Millau Viaduct is to the Aveyron. The comparison might be considered particularly apt, not only because of the essentially technical nature of the two structures, but also because the Viaduct was built by Eiffage, the contemporary successor of Gustave Eiffel’s own construction company. The designers were pleased to point out that the steel deck of the Millau Viaduct weighs 36 000 tons, which is to say four times more than the Eiffel Tower. As it happens, Gustave Eiffel himself worked in the region between 1882 and 1884, build- ing the Garabit Viaduct, a railway arch bridge over the Truyère River at Ruynes-en-Margeride (page 476). At the Viaduct’s opening on December 14, 2004, President Jacques Chirac stated:

The Millau Viaduct is a magnificent example, in the long and great French tradition, of audacious civil engineering structures, a tradition begun at the turn of the nineteenth and twentieth centuries by the great Gustave Eiffel.8

Though it appears to almost hover over the Tarn River valley in all of its rural splendor, the Millau Viaduct thus in some sense embodies an incredibly rich history that reaches back to the time of the Romans, continuing with the stream of pilgrims headed toward Santiago de Compostela, and brought to modern life with the A75 highway, also called La Méridienne (The Meridian), going north to the center of France. A meridian is of course an imaginary circle, traced on the surface of the globe, leading from one pole to the other. In this case the meridian in a sense bisects the map of France and crosses over its geography and through its history. Descriptions of the Viaduct tend to be rather technical or full of impressive figures, but what strikes those who see it most is its lightness. When the engineer Virlogeux stated, “From the global idea, you can form the detailed shape, so that it expresses the flow of forces and can enhance the structural concept,” he was referring to his own collaboration with the architect Norman Foster. In a way, it is also Jacques Chirac who best explained the architectural or engineering significance of the Millau Viaduct, pointing out its affiliation with Gustave Eiffel and his tower or the Garabit Viaduct.9 The engineer at Millau was indeed French, even if the subtle refinements introduced by Norman Foster surely made the bridge the vision of lightness that it is. Odd that Millau was once British, a land of invasions ruled by the Romans, Aragon, and Barcelona before finally assuming its profoundly French identity. It is the combination of the knowledge of the French engineer and the esthetic, functional sense of the English architect that made the Millau Viaduct one of the most artistic pieces of civil engineering of the early 21st century, and a fitting monument to the rich valley that it passes over.

1. http://whc.unesco.org/en/list/868
2. Sir Norman Foster in discussion with the author, Châteauneuf-Grasse, France, July 21, 1996
3. http://www.jfccivilengineer.com/le_concepteur.htm
4. http://www.fzt.haw-hamburg.de/pers/Scholz/dglr/hh/text_2010_10_28_Millau_ Viaduct.pdf
5. Valéry Giscard d’Estaing, “Viaduc de Millau : Giscard écrit à Chirac, ” Le Figaro, August 18, 1996. “Ce projet me parait appeler les plus graves réserves, c’est pourquoi je me permets de vous saisir de cette question en vous demandant de réexaminer cette décision… Or le projet envisagé pour Millau appartient à la famille des pont haubanés, construits pour les entrées de port ou les estuaires des fleuves… Lorsqu’il s’agit, par contre, d’un ouvrage situé à grande hauteur, on doit rechercher un profil moins opaque et moins oppressant pour le paysage.”
6. Norman Foster, Le Moniteur, August 2, 1996, ”Réciprocité” “Loin de nous l’idée de nier le talent dont fait généralement preuve le vainqueur, le britannique Sir Norman Foster. Loin de nous, à l’heure de l’Europe, d’avancer le moindre argument de préférence nationale, même si la profession d’architecte est, en France, sinistrée. Ne pourrait-on, en revanche, imaginer, au nom de cette même Europe, qu’un cabinet français se voit ouvrir aussi généreusement les frontières de l’architecture anglaise, italienne ou espagnole, un jour prochain ? »
7. http://www.iabse.org/IABSE/association/Organisation_files/Outstanding_ Structure_Award/Millau_Viaduct__France.aspx
8. Le viaduc de Millau s’inscrit magnifiquement dans cette longue et grande tradition française d’ouvrages d’art audacieux, tradition ouverte au tournant des XIXe et XXe siècles par le grand Gustave Eiffel, auteur, à quelques dizaines de kilomètres d’ici, du viaduc de Garabit. Tradition poursuivie, plus près de nous, avec les ponts de Tancarville, de l’île de Ré et de Normandie.
9. http://www.jacqueschirac-asso.fr/archives-elysee.fr/elysee/elysee.fr/francais/ interventions/discours_et_declarations/2004/decembre/fi001239.html