The design of the access infrastructure for Expo 2015 forms a system of radial flows through the otherwise impassable boundaries formed by motorways and railways. It comprises a bridge-viaduct-bridge-tunnel sequence across an extremely important but profoundly diversified piece of land at the intersection of major traffic flows between the city of Milan and Western Europe.
The closeness of the infrastructure to the Expo site and its distinct architectural and morphological characteristics such as the Mediterranean Hill served as an initial stimulus and point of departure to create artificial landscapes. In addition, the functions required around the base – such as the southeast entry, the east car park and the people-mover arrival point – entailed a study of lightness, permeability, transparency and continuity.
In the height, length and positioning of the five continuous and diversely structured arches, the proposal clearly defines the general plan while also correctly relating to the profiles rising from the Expo: not one of the different forms built dominates the others. The two double-arch bridges on the A4, the single-arch one on the A8, and the embellishment arches of the Expo viaduct are part of a single entity: there is complete integration between them, which promotes new visual relations. Underlining the continuity the different elements is the greyscale colour project by the artist Jorrit Tornquist.
The fact that we opted for these structural and aesthetic models also arises from the need to guarantee maximum visual permeability both to users of the motorways entering and exiting Milan, and to visitors arriving from the Expo’s east car park. In the case of the arch bridges, the structural type has given remarkable transparency and lightness due to the absence of piers over a span of about 140 metres on the A4 motorway and of about 95 metres on the A8.