Route des Grandes Alpes is signposted with large brown pannels in both directions all along the 720 km between Thonon and Nice.
Route des Grandes Alpes is a high mountain road, and in winter it’s snowbound.
• Most of the passes are open at the end of May. But the highest ones – Iseran, Galibier and Izoard – are clear only after mid-June, at the earliest.
• The passes are open until around the end of October. They generally close when the first snows arrive.
• But of course you can also make your own selection of stages, including variants that take in the lower valleys.
Worth knowing : Some passes are open all year round, notably Gets, Aravis, Saisies, Télégraphe, Lautaret, Vars, Couyolle, Saint-Martin, Turini and Castillon.