The project retrofits Route SS 3 Flaminia in the section between Spoleto and Foligno to type III of CNR standards.

Final design envisages technical solutions to comply with the provisions contained in the Environmental Impact Assessment, with particular regard to the level indicators with respect to the superficial water network, with which the track of the previous project interfered in some parts.

The track extends for a length of about 18 km, passing through the Municipalities of Spoleto, Campello sul Clitunno, Trevi and Foligno.
The infrastructure includes 4 split-level junctions, 11 boxed underpasses, 4 viaducts with lengths of 100 m, 345 m, 235.40 m, and 717 m, 6 overpasses, 3 artificial tunnels.

The major crossings regard the railway and Clitunno river, and provide viaducts with multiple spans. Artificial tunnels provide adequate shelter for the crossing of the town of Fabbreria and a particular resolution of the junction of Campello.