Traversing the international Bielsa Tunnel in the Pyrenees

Tunel Bielsa-Aragnouet is an international high mountain tunnel at an elevation of 1,820m (5,971ft) above sea level, located on the border of Spain and France.

Tunel de Bielsa

Where is Bielsa Tunnel?

Opened to traffic in October 1976, the tunnel passes through the Pyrenean chain between Aragnouet and Bielsa, linking the Hautes-Pyrénées department in southwestern France and the province of Huesca, Aragon, in northern Spain. The highest point of the route is at the north portal, on the French side.

How long is the Bielsa tunnel?

Set high in the Pyrenees mountain range, the tunnel is 3.07km (1.90 miles) long: 1,298m are in Spain and 1,772m in France. It is toll-free. The two-lane tunnel is bi-directional for light vehicles and alternating in one direction for trucks, buses, and caravans.

Is the Bielsa tunnel paved?

On the Spanish side, the road to the tunnel is called A138. It’s fully paved. Starting from Salinas, the ascent is 21 km long. Over this distance, the elevation gain is 1,028 meters. The average percentage is 4.9%.

On the French side, the road to the tunnel is called D173. It’s asphalted but in worse conditions. Starting from Saint Lary Soulan, the ascent is 18.93 km long. Over this distance, the elevation gain is 1,000 meters. The average percentage is 5.3%. The maximum gradient is 11.8%.

Is the Bielsa tunnel open?

The road is typically open all year round, with occasional closures in winters (between 7 and 10 days per season) due to dangerous weather conditions and the risks of avalanches at its entrances. Traffic is prohibited for vehicles carrying hazardous materials and exceeding 4.3 meters in height.