Key facts
Total length of 13.27 km in four tunnels. Excavation using a 15.2 m diameter EPB (2008 World Record in diameter and power). The cross-section comprises an upper area 13.76 m wide with 3 lanes, shoulders and pavements and a lower level exclusively for emergency vehicles.
Geology: pre-consolidated tertiary soils and soft rocks (gypsum), presence of alluvial channels and anthropogenic fill.