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Kadagua Corridor


The construction coming into service of the Kadagua Corridor motorway will organise the Las Encartaciones region by connecting it to Greater Bilbao by means of a new two-lane highway, to take pressure off the BI-636 trunk road, which is used by around 25,000 vehicles on average every day.

The three sections pending for the completion of the corridor have been included in the PEAB 2003 their construction has been entrusted to Interbiak.

  • The Alonsotegi Bypass (Kastrexana-Arbuio) (4.4 km).
  • Arbuio-Sodupe, (5 km).
  • Widening the road to four lanes between Padura Aranguren (5.8 km).

Serviced Areas

The zones that the Cadagua motorway will serve are the towns in the River Cadagua valley, between Bilbao the province of Burgos: Alonsotegi, Güeñes, Zalla Balmaseda, along with the other towns of the Enkarterri region.

Main Characteristics

The Alonsotegi Bypass involves building a two-lane dual-carriageway in the municipal districts of Bilbao Alonsotegi, with a total length of 4.4 km, which starts at the Kastrexana link road, where it continues the existing section between the A-8 Motorway Kastrexana, ends at the Arbuio link road. There is a third connection between these two hubs, the Alonsotegi link road, which leads to that town.

The Alonsotegi Bypass runs along the slopes of the right side of the valley of the River Kadagua. This was a particularly challenging project given the rough terrain, with steep slopes, which generated steep gradients on the left bank significant walls on the right bank.

The Abruio-Sodupe section provides continuity as it connects the Alonsotegi Bypass to the Sodupe-Artuxbe section thus creates a bypass for the section Zaramillo (km 11) to La Cuadra. The new section runs along the foot of the slopes along the right bank of the River Kadagua, on a strip of land under the Ordunte Canal. The core section of dual-carriageway here is 4.8 km long. The most important structures include the Zaramillo tunnels, close to the Arbujo link road, which are 200 m long.

The Padura-Aranguren section has been widened to two lanes each way, between the Padura Aranguren links roads, involveing 5,800 metres of new road surface. Its capacity has thus been expanded to complete the Kadagua Corridor, an infrastructure that provides a link to the Greater Bilbao Area capable of handling a traffic flow of over 10,000 vehicles a day.

Current Status Of The Project

  • Alonsotegi Bypass Came into service: 24 March 2007.
  • Arbuio-Sodupe Came into service: 13 March 2008.
  • Padura-Aranguren Came into service: 5 December 2006.


Kadagua Corridor