New construction section Gerediaga-Elorrio.

The section begins at the connection with the AP-8 motorway at Gerediaga, in the municipality of Abadiño. It runs to the west of Elorrio, where, by means of a new junction, it connects with the BI-632, giving continuity to the Elorrio Bypass.

It has a total length of 6.44 km, with separate two-lane carriageways along its entire length.

In the Muntsaratz area, a new junction connects this corridor with the N-636, providing the towns of Abadiño and Atxondo with access to the new axis.

A large part of the route runs through tunnels. The Gaztelua I and II tunnels consist of two tubes and are 594 m and 1,141 m long respectively. Between the two is the Gaztelua artificial tunnel, 216 m long. There is also the Atxondo cut-and-cover tunnel, with a total length of 95 metres.

The main works included are, firstly, two viaducts that serve as the base for the connection of the new infrastructure with the AP-8, measuring 865 m and 649 m, one of which is divided to provide a branch, also as a viaduct, measuring 187 m.

The main technical characteristics of the new route are summarised below.

• Number of tunnels / cut-and-cover tunnels: 4
  • Gaztelua I tunnel:
    • Longitude: 594m
    • Number of tubes: 2
  • Gaztelua II tunnel:
    • Longitude: 1.141 m
    • Number of tubes: 2
  • Falso túnel de Gaztelua:
    • Longitude: 216m
    • Number of tubes: 2
  • Falso túnel de Atxondo:
    • Longitude: 95m
    • Number of tubes: 2
• Number of junctions/intersections: 3
• Number of viaducts: 8