This climb is a nice little switchback road which means the descent, on foot, is fairly short.  The descent is down a steep track from the chapel and fairly quick.

Official RouteFrom Bourg d'Oisans to l'Alpe d'Huez. 21 hair pins. 13.2km. Start at 744m, Summit 1815m. Average gradient 8.1%, sections of 12% over 100 meters.