The route of the Modane - Alpe d’Huez stage has been changed: the peloton will climb the col de la Croix-de-Fer pass before tackling the final run, for a stage that from a sporting point of view remains generally unchanged.

Kept on alert since the closure of the Chambon tunnel because of a landslide in April, Tour de France organizers have been informed by the Isère authorities of the inability to restore circulation before the passage of the race scheduled on 25 July. Despite the determination of all parties involved to conserve the original route, but more importantly to allow the population of the communities concerned to return to their normal traffic patterns, it was decided that the route of stage 20 be changed. The start in Modane Valfréjus and arrival at Alpe d'Huez are maintained.

After putting in a new reconnaissance run, the organizers of the Tour de France opted for a route with the same distance at 110.5km. The peloton will leave Modane at 1.15 PM as was scheduled, then will head north after traversing Saint-Michel-de-Maurienne. The col du Galibier pass will no longer be part of the 2015 edition, however the peloton will climb the col de la Croix de Fer pass a second time, attacked from a different slope than the day before on stage 19. The riders will then plunge down into the Oisans Valley and find themselves in Bourg-d’Oisans (km 94. 5) and re-join the original itinerary, before beginning the climb to Alpe d’Huez. As a result of this course change, the Henri Desgrange prize, which rewards the rider who leads at the highest point of the Tour, will be awarded at the col d’Allos (2,250 m), just prior to the finish of stage 17 at Pra -Loup.