The design involved extraordinary maintenance works for the upgrading of the existing highway section. The section under intervention includes no.7 viaducts, no.3 tunnels and some minor works minor (retaining walls, minor overpasses, bridges, manholes). Specifically, the interventions involved: resurfacing of the road pavement; resurfacing safety barriers and road signs; hydraulic works for water regulation platform; rehabilitation of deteriorated reinforced concrete works; remaking of expansion joints expansion on viaducts; waterproofing of viaduct deck; green works and environmental mitigation; junction lighting system; upgrading to the current regulations of tunnel lighting systems.