Collado de Urdiceto: Driving the 11.10% Piste in the Aragonese Pyrenees
Reaching an elevation of 2,330m (7,644ft) above sea level, Collado de Urdiceto (also known as Collado de Ordizeto) is a high mountain pass located in the comarca of Sobrarbe, in the Huesca province of northern Spain. Situated in the Pyrenees, it is recognized as one of the highest roads in the country.
| Road facts: Collado de Urdiceto | |
|---|---|
| Location | Huesca, Aragon, Spain |
| Elevation Gain | 1,122 m |
| Length | 10.1 km (6.27 miles) |
| Average Gradient | 11.10% |
| Surface | Unpaved / Loose Gravel |
How is the road to Collado de Urdiceto?
The ascent to Collado de Urdiceto begins near the village of Parzán, starting from the paved A-138 road. The track is 10.1 km (6.27 miles) long and is entirely unpaved, consisting of loose gravel and rocky sections. Over this distance, the road overcomes a massive elevation gain of 1,122 meters, resulting in a sustained average gradient of 11.10%. Due to the technical difficulty and the continuous steep ramps, a high-clearance 4x4 vehicle is mandatory for any motorized transit.
How many vehicles can pass at once on the road to Collado de Urdiceto?
The track to Collado de Urdiceto is exceptionally narrow and is impassable for two cars at the same time in the majority of its sections. There are very few passing points, requiring drivers to anticipate oncoming traffic. The geometry of the road includes tight switchbacks and shelf sections carved into the mountainside. Near the summit, the route provides access to the Refugio del Paso de los Caballos, a basic mountain shelter used by workers and experienced mountaineers navigating the Central Pyrenees.
What are the weather hazards on the road to Collado de Urdiceto?
Due to its high altitude, Collado de Urdiceto is usually impassable from October to June due to heavy snow accumulation. Summer thunderstorms are a significant risk factor, as heavy rain can quickly erode the unpaved surface, creating deep ruts or making the gravel extremely slippery. Rapid cloud development can also result in zero visibility on the narrowest parts of the track. Drivers must be prepared for extreme temperature drops, even during the peak summer months, and monitor tire traction on the 11.10% slopes constantlly.
What is the driving strategy for the road to Collado de Urdiceto?
Navigating the 1,122m vertical climb to Collado de Urdiceto requires advanced off-road skills. The use of low-range gearing is essential to manage engine temperature during the ascent and to provide reliable engine braking on the descent. Braking systems are subject to extreme thermal stress, and reliance on foot brakes alone will lead to brake fade. It is critical to check the mechanical status of the 4WD system before starting the track from Parzán, as the lack of safety barriers and the loose terrain leave no margin for mechanical failure.
Pic: Keith Rose