Driving the steep D308 to Col de la Ramaz: The challenge of Tunnel de Sommand

# Col de la Ramaz: Alpine Drama Meets World-Class Views

Perched at 1,619m (5,311ft) in the Haute-Savoie region of France, Col de la Ramaz is the kind of mountain pass that gets your adrenaline pumping before you even start driving. This isn't just any Alpine crossing—it's a Tour de France legend that connects the Giffre valley to the Praz de Lys ski area, and it absolutely lives up to the hype.

The real magic (and challenge) happens on the 14 km ascent from Mieussy, where you'll tackle some seriously steep gradients pushing 10-12% as you approach the notorious Tunnel de Sommand. This isn't a gentle cruise—your cooling system and brakes are going to earn their keep, especially if you're piloting a campervan or towing anything substantial.

Now, the Tunnel de Sommand is where things get properly intense. Built to bypass a sketchy section of road literally hanging off a limestone cliff, this narrow, dimly-lit passage is the definition of a "balcony road." Even with modern improvements, it remains genuinely thrilling—damp pavement in summer, minimal visibility, and heart-stopping glimpses of the drop through rock openings. Add cyclists (tons of them) into the mix, and you've got a section demanding 100% focus.

After you punch through the tunnel, the landscape opens up beautifully onto the Sommand plateau. It's your moment to breathe before the final push to the 1,619m summit, where the reward is absolutely worth it: Mont Blanc and its snow-capped peaks dominate the horizon on clear days. It's genuinely stunning.

The full 23 km route runs west to east and eventually feeds into the D902—part of the legendary Route des Grandes Alpes. Just remember: descending back toward Mieussy requires serious brake discipline. Use your engine to control speed on those continuous steep sections and tight turns, or you'll risk overheating your brakes spectacularly.

Best driving windows? Late May through October. Winter closures due to snow and storms are common, so timing matters. It's a road that perfectly blends Alpine beauty with technical driving that demands respect.