Col de l'Iseran is the King of the Alps and the holy grail for many motorcycle and bike tourers. It’s the highest paved mountain pass in the Alps, at an elevation of 2.764m (9,068ft) above the sea level. The pass is traversed by the D902 road. It's one of the highest mountain roads of Europe.
Col de l'Iseran is part of the Graian Alps, and it is situated in the department of Savoie in France near the border with Italy. The climb is included in the touristic Route des Grandes Alpes and links the valley of the Isère and the valley of the Arc River between Val-d'Isère in the north and Bonneval-sur-Arc in the south. The north side of the pass road includes several galleries and tunnels, with a maximum grade of 12 percent.
This road is open only in summers, from May or June to October. With such a high summit altitude the road can be closed anytime due to snowfalls. The zone is prone to heavy mist and can be dangerous in low visibility conditions. On certain summer days, the road from Val d'Isère to the Col d'Iseran is closed to all traffic except cyclists. The pass is traversed by the scenic Route des Grandes Alpes.
At the top there’s a sign saying a height of 2.770m but it’s wrong. Maps report 2.764m. The surface of the road over the pass is asphalted. Since 1947 the pass has been used several times on the Tour de France. The route forms part of the famous series of cols linking the Northern Alps to the Cote d'Azur. It's one of the highest mountain roads of the country.
This is an exquisite winding mountain drive with sharp and blind curves and hairpin switchbacks leading the traveler over the mountains. The col road was constructed between the First and Second World Wars and took an astounding 34 years to complete, finally joining the Maurienne and Iseran valley systems for the first time in history.The route has existed for hundreds of years as mule pass and became an official road following a presidential decree in the 1920s with 600 workers toiling to make the road which was opened in 1937.
There are 3 routes to reach the summit. From Bourg Saint Maurice, the ascent is 48 km long, gaining 1.955 meters with an average percentage of 4.1 %. From Lanslebourg - Mont Cenis, the ascent is 32.9 km long, gaining 1.371 meters with an average percentage of 4.2 %. And starting from Bonneval sur Arc, the ascent is 13.43 km long, gaining 977 meters, with an average percentage of 7.3 %.