Dangerous Roads

Mont Cenis is a massif and pass (el. 2083 m / 6827 ft) in Savoie in France which forms the limit between the Cottian and Graian Alps. A road over the pass was built between 1803 and 1810 by Napoleon.

A Fell mountain railway system, named after its inventor John Fell and worked by English engine-drivers, was opened alongside the road in 1868, but was dismantled in 1871, on the opening of the Mont Cenis Tunnel. For the railway through the tunnel see Fréjus Rail Tunnel.
This tunnel (highest point 1295 m / 4249 ft) is really 27.4 km 17 miles west of the pass, below the Col du Fréjus. From Chambéry the line runs up the Isère valley, but soon bears through that of the Arc or the Maurienne past Saint-Jean-de-Maurienne to Modane (98.2 km / 61 mi from Chambéry). The tunnel is 13 km in length, and leads to Bardonecchia, some way below which, at Oulx the line joins the road from the Col de Montgenèvre.

Thence the valley of the Dora Riparia is followed to Turin (103.8 km / 64.5 mi from Modane).



The carriage road mounts the Arc valley for 25.7 km / 16 mi from Modane to Lanslebourg, whence it is 12.9 km / 8 mi to the hospice, a little way beyond the summit of the pass. The descent lies through the Cenis valley to Susa (49.9 km / 37 mi from Modane) where the road joins the railway.



To the south-west of the Mont Cenis is the Little Mont Cenis (2184.2 m / 7166 ft) which leads from the summit plateau (in Italy) of the main pass to the Etache valley on the French slope and so to Bramans in the Arc valley. This pass was crossed in 1689 by the Vaudois, and by some authors is believed to have been Hannibal's Pass.

 

Being a pass in the Alps, the Mont Cenis was used in several notable incidents in history. One example is the descent of Constantine I to Italy, to fight against Maxentius.

It was the principal route for crossing the Alps between France and Italy until the 19th century. It was also used as the main passage by which Charlemagne crossed with his army to invade Lombardy in 773.

 

There are 2 ways to get this pass:



Starting from Lanslebourg, the Col du Mont Cenis ascent is 9.84 km long. Over this distance, you climb 682 heightmeters. The average percentage is thus 6.9 %. The climb is very simple: a sequence of five hairpins, with a beautiful wide road, very regular and perfectly surfaced. The slope is nearly constant (7%) and the road is protected from the sun by big trees, almost all along. The summit is reached after a last sequence right-left turn in a big curve.

 

Starting from Susa, the Col du Mont Cenis ascent is 30.51 km long. Over this distance, you climb 1581 heightmeters. The average percentage is thus 5.2 %.