6.44km long, with separate dual carriageways the length of the route. A new link road connects the corridor with the N-636 near Muntsaratz, facilitating access to a new road to the towns of Abadiño and Atxondo.
A large part of the route runs through tunnels. Gaztelua I and II are two tunnels of 594m and 1,141m, respectively. Between them is a 216m-long artificial tunnel also, and there is also a 95m false tunnel at Atxondo.
The main work also includes two viaducts, 865m and 649m long respectively, serving as the basis for the connection of the new infrastructure to the AP-8. One of these branches off to another smaller viaduct, 187m long.
Location: Gerediaga, in the province of Biscay in the Basque Country
Contract type: Design, construction, financing, operation and maintenance
Infrastructure: 6.44km highway with separate dual carriageways the length of the route
Year of completion: 2016