The Millau Viaduct extends on the La Méridienne highway that connects Clermont-Ferrand to Narbonne. It crosses the Tarn valley from the Causse Rouge in the north to the Causse du Larzac in the south. It has relieved the town of Millau of the thousands of motorists who had to cross it until it was put into service in 2004. Controversial at the time of its construction, it has contributed to the reputation of the region and the development of more sustainable and environmentally friendly tourism.