The intervention consists of a project to upgrade S.S. 372 “Telesina” to 4 lanes, covering a design stretch from km 36+100 to km 61+200, from San Salvatore Telesino to Benevento. This upgrade strengthens the connection along the Lazio–Campania–Puglia corridor via the A1 (Rome–Caianello) – SS 372 (Caianello–Benevento) – Raccordo Autostradale (BN/A16) – A16 (Castel del Lago–Bari), providing a viable alternative to the current motorway route in an area heavily affected by intense freight traffic.

The detailed design was developed based on the final design, taking into account, as far as possible at this design stage, the requirements and recommendations set out in the CIPE Resolution of 24/07/2019, and integrating improvements proposed during the tender phase. As part of this design stage, a field investigation campaign was carried out, including geotechnical, seismic, and structural surveys, to ensure optimal definition of the works to be executed. In addition, topographic surveys were updated.

Particular attention was given to the study of construction staging and execution phases, considering the need to maintain operation of the existing infrastructure throughout the duration of the works. Compared to the awarded project, it was necessary to identify new quarries and disposal sites, as the existing conditions had changed significantly since the tender stage. This situation arose primarily due to both spatial and temporal interference with the works of the new Naples–Bari high-speed line by RFI, which heavily impacted the project’s construction planning.

Specifically, during this design phase, a new deviation of the Telesina near the Ponte/Torrecuso junction was designed, as the solution proposed in the final design interfered with areas occupied by the RFI construction site.