Tunnels are going to get you in the Alps. The trick is to be prepared. Some tunnel entrances even say that cycling is prohibited, yet offer no alternatives...

The old road, in this case, offered an alternative route to the busy main road. Re-joining the main road to Moutiers we then headed towards Pralognan-la-Vanoise.

TIP: It is wise to plan a route so that tunnels you meet are always on a downhill. Then if there's no alternative, hold your breath, wait fo a good gap in the traffic, put all your lights on, and pedal like you mean it!

With a through draft, 54mph (80+kph) is possible.