The Supersur relief road is designed to decongest traffic on Biscay’s roads.

The Supersur, together with the tunnel under the river, is a key project for decongesting traffic at the three busiest points on Biscay’s roads: La Avanzada, Rontegi Bridge and the A-8 motorway as it passes Max Center, which are used on a daily basis by two out of three vehicles in Biscay.

The building work for its opening in the spring of 2023 is proceeding according to plan. The winter of 2019 witnessed the opening of the mouth of the Seberetxe tunnel, and the Arnotegi tunnel is advancing at a steady pace, and 50% of its total length has already been excavated: 816 metres in axis 1 and 884 in axis 2. The summer of 2020 has seen the replacement of the pile on the AP-68 motorway.

The thinking behind the Supersur in Biscay

The second phase of Supersur involves its connection from the Peñascal junction to the AP-68 motorway with a view to exploiting the full potential of an artery that is being used by increasingly more traffic.

When this phase is completed in the spring of 2023, the A-8 and the Port of Bilbao will be connected to the AP-68. The link-up between these two motorways will constitute the first major step toward organising local traffic, reducing congestion, and making our roads safer.

The purpose of the Supersur

  • This second phase will complete the building of the Supersur, which will be used by 24,000 vehicles per day.
  • The Supersur and the tunnel under the river, which is scheduled to open in 2027, will form a vast road network referred to as the 'gran variante de Biscay', connecting the metropolitan area in Biscay with the country’s hinterland and the rest of the northern coastline, reducing congestion and freeing up our towns and villages.