Adaptation of the section of roadway S.S. No. 4 "Salaria" between the Valgarizia tunnel and Acquasanta Terme

Highways and Roads Bridges and Structures




S.S. No. 4 "Salaria"



Cost of work

185,56 M€

Purpose of provision

Technical-economic feasibility project

Project overview

The intervention concerns the upgrading of the section of the S.S. No. 4 "Salaria" roadway between the Valgarizia tunnel and Acquasanta Terme (Lot 2 from km 155+400 to km 159+000). The route in the different design configurations provides a new road system as a variant, of about 5 km, with respect to the existing SS4 Salaria and reconfigures the existing staggered-level junction north of the built-up area of Acquasanta Terme and the connections with the local road system. The solution involves exclusively the slope to the left of the river, which does not present morphogenetic phenomena and also encounters a favorable hydrogeological situation, allowing to have a route with satisfactory plano-altimetric characteristics, also in consideration of the fact that

runs mainly underground. The high percentage of underground works, while resulting in a significant increase in construction costs, allows the work's impact on the surrounding environment to be minimized


Sintagma's activities covered the technical-economic feasibility project, which included:

  • Environmental Study and Acoustic Study;
  • Archaeological, Geological and Geotechnical, Hydrological and Hydraulic Study.
  • Technical Economic Feasibility Project of approximately 5 km variant, single 2-lane roadway (cat. C1);
  • Complete staggered-level interchange at Acquasanta Terme and exit at Favalanciata for those coming from Rome;
  • 6 viaducts, including 4 at the Acquasanta Terme interchange with a total length of about 1.11 km;
  • 2 natural tunnels with a total extension of 4.11 km;
  • Work organization program;
  • Expropriations and interference with underground utilities.