As the roads are closed to traffic, you can probably end up doing 60+ mph if you've a mind to. Being older if not wiser than I used to be, I tend to ease off at 45 these days. If you like tunnels, take a ride up to Villard Notre-Dame above Bourg D'Oisans, plenty of unlit tunnels on that short bit of road. You may regret choosing to stay in Huez....
As the roads are closed to traffic, you can probably end up doing 60+ mph if you've a mind to. Being older if not wiser than I used to be, I tend to ease off at 45 these days. If you like tunnels, take a ride up to Villard Notre-Dame above Bourg D'Oisans, plenty of unlit tunnels on that short bit of road. You may regret choosing to stay in Huez....