Tunnel du Galibier is a high mountain tunnel at an elevation of 2.576m (8,451ft) above the sea level, located on the border of Savoie and Hautes-Alpes departments, in south-eastern France. Before 1976, the tunnel was the only point of passage at the top. The tunnel was closed for restoration until 2002, and a new road was constructed over the summit.
Located roughly a kilometre from the actual Col du Galibier summit, the surface of the tunnel is asphalt. The pass was first made crossable for military purposes in 1879. A mule track had existed over Galibier well before that year. The tunnel was built in 1890 and opened one year later, in 1891. The tunnel was in use 85 years, until 1976 when, because of its poor condition, the tunnel was closed and reopened in the summer of 2002. The only bar-restaurant near the summit of the pass is located just before the tunnel.
Between 1976 and 2002, with the oak-doored tunnel closed and suffering extensive repairs, it was built the new road over the summit, and riders had to take the D902B road. Until 1976, all traffic, including the Tour de France, passed through the oak-doored darkness of the summit tunnel.
The tunnel is said to be 365 metres long -a metre for each day of the year- and has been traversed by the Tour de France several times. The tube is four meters broad (the roadway /carriageway is 3.2m wide); a single lane controlled by traffic lights, which can be passed only alternately. It’s among the highest such installations in Europe. Due to the altitude of the climb it's uncommon to get snow storms on its summit during mid-summer.
The tunnel is closed to bicycles, caravans and trucks over 19Tn. It’s impassable from late October to late May-early june. At the south entrance to the tunnel there is a memorial to the father of the Tour de France, Henri Desgrange, who initiated the Tour de France in 1903. It was inaugurated on 19th July of 1949. He loved the Col du Galibier and once wrote "In front of this giant we can do nothing but take our hats off and bow". Desgrange was editor of L’Auto at the time and used the Tour as a way of increasing circulation of the publication. L’Auto was printed on yellow paper, hence the colour of the yellow jersey worn by the race leader.