The minister of Development, José Blanco, accompanied by the national government's deputy in Asturias, Antonio Trevín, the head of the Infrastructure Department of the Principality of Asturias, Francisco González Buendía, and other local authorities, plus FCC Chairman Baldomero Falcones and Avelino Acero, general manager of FCC Construcción, went to the Las Dueñas/Muros del Nalón section of the Autovía del Cantábrico (A-8) in Asturias on 10 April last to supervise construction. The Ministry of Development has put more than 150 million euro into this section.

The work consists in a section of newly designed dual carriageway 8.3 kilometres long. The section has separate roadways that lie in the municipal limits of Cudillero and Pravia, running nearly parallel to road N-632 to the south. The layout is designed to connect the Muros de Nalón and Lamuño junctions.

The most interesting parts of this section of road are five viaducts (la Concha de Artedo, Santa Ana, San Juan, Piñera and Santa Olaya), measuring between 160 and 1,188 metres in length, and two tunnels (San Juan and Somado), designed as double tunnels whose lengths vary between 221 metres for San Juan Tunnel on the northern roadway and 501 metres for Somado Tunnel on the southern roadway.

La Concha de Artedo Viaduct is the most striking part of the section, as it will be the longest structure and the structure with the highest pier height that has ever been built in the Principality of Asturias.

The viaduct is a single-deck structure with a double roadway. It is 1,188.4 metres long and 22.8 metres wide. It has 17 spans a maximum of 75 metres across. Its maximum pier height is in excess of 100 metres.

The section also has five undercrossings, eight walls, eight cross-drainage culverts and the Cudillero junction. This is a complete trumpet junction that leads to a roundabout, where the section intersects with road N-632 and road CU-3 (the Cudillero access road). This junction neatly takes care of all the traffic flows connecting the dual carriageway with road N-632 and the town of Cudillero.

The dual carriageway has two roadways. Each roadway has two 3.50-metre-wide lanes, a 2.50-metre outer verge and a one-metre inner verge, except at the end of the section, where there is an extra lane.