Construction of the new railway site in the urban stretch through Rome of the Rome–Naples section of the Italian High Speed Railway Network, between progressive km. 2+273 and km. 4+420 (as per project) and for the laying of the second track of the Rome – Sulmona line between progressive km. 0+000 and km. 1+458 (as per project), as well as for the interconnection between the Rome–Naples High Speed Railway Network and the Rome–Florence Express Railway network, consisting of civil engineering works and provisional and definitive modifications to the superstructure and to the technological systems during the work phases, and of the adapting of existing stops/stations, including the construction of pavements, cantilever roofs, underpasses, and the technical systems of the buildings.