The greenway named Via Chambon is open to walkers, cyclists, rollerbladers.... It is a new use of the emergency road built in 2015 on the left bank of the lake of Chambon after the closure of the large tunnel weakened by a major landslide. Developed and secured, this 5.3 km route is transformed into a greenway during the summer, with the added bonus of an exceptional panorama of the lake of Chambon

More information on their website

What if I went by bus?

Take the T73 Grenoble-Bourg d'Oisans-Les Deux Alpes line and get off at the "Barrage du Chambon" stop