At the time of its construction, the Coretta overpass was the first Italian highway overpass made of a collaborating reinforced concrete-steel compound system, and was also one of the largest bridges in the world of this type. This overpass also represented a unique opportunity throughout the highway, for its use
of steel in the construction of three spans, approximately 63m each, with 4m high solid wall beams - despite Francesco Aimone Jelmoni, designer of the entire industrial plan, had initially thought of the overpass as a parabolic arch bridge. The beams were produced by ILVA, which mainly produces and
transforms steel, and designed by two of its technicians: Carmelo Romani and Fabrizio De Miranda himself.
The structure was very complicated to assemble and for this reason an Innocenti scaffolding was used; at first, it was placed in the centre, and then it was shifted to the left.