The , also called the and , is a highway () that connects all the regions on the northern coast of Spain. It connects Baamonde in Begonte, Galicia to Bilbao, where it continues as the Autopista AP-8 to the French border. The road passes Ribadeo, Avilés, Gijón, Santander and Bilbao.
The A-8 is the main beltway of the Greater Bilbao conurbation, which has about a million inhabitants in the metropolitan area. The of the highway that passes by Bilbao and its metropolitan area, from Galdakao to Muskiz, suffers from considerable traffic congestion.
A new toll by-pass of the city, known as is being built. The by-pass will be long. Under the Pagasarri range most of it will be in tunnels, as there is no physical space to build it elsewhere.