An ancestral communication route through the Alps, the Lautaret pass in the Hautes-Alpes department is also famous for its landscapes, its alpine botanical garden, and the numerous passages of the Tour de France. The worldwide renowned cycling competition is expected to return to Lautaret in 2022. At 6,748 ft (2,057 m) above sea level, it is also the highest French pass open to car traffic all year round, even if the snow conditions sometimes impose temporary closures. The Lautaret's relatively gentle slope with an average gradient between 3.1 and 3.8 % derives from the origin of its relief modeled by the Romanche-Guisane glacier in a threshold of glacial diffluence.