A 44 km segment of Italy’s Direttissima
high-speed line between Arezzo Sud and Figline Valdarno, engineered through Tuscany with 15 km of tunnels, the 1,716 m Arno Viaduct, and 100 supporting structures.

The project comprises the Arezzo Sud–Figline Valdarno stretch and the two interconnections at Arezzo Sud and Valdarno Sud. The line was designed for a maximum speed of 250 km/h and a minimum horizontal radius of 3,000 m, with longitudinal gradients capped at 7.5% in tunnels and 8% on open line.

To achieve an alignment as free as possible from the region’s orographic obstacles, the design integrates a substantial program of major infrastructure: 15 km of mined and cut-and-cover tunnels, multiple bridges and viaducts — anchored by the 1,716 m Arno Viaduct — and 100 minor structures including hydraulic culverts, overpasses, and underpasses.