La dimensione sotterranea della città: funzionalità e smartness del progetto urbanistico

The city if facing strong problems due to the unsustainability of its form and of its weight on the environment; for this reason the underground city is an interesting solution in the building of a sustainable city. Thinking to the third dimension under our feet is to imagine a future where it is possible to transfer functions and activities improving in this way the environment balance of the urban structures. Not all the cities are in the condition to take advantage of this possibility, but new possibilities open and new urban structures are in the ropes of mankind. Above all in the great cities it assumes strong urban planning connotations because the underground represents an important resource and its employment can have considerable consequences on the urban performance. The use of the underground space is the occasion to develop a new meaning of the planning, careful to all the occasions that are present in an urban scenario but also careful to the sustainability of the building of the urban space. Mobility, commerce, logistics, leisure are some of the functions transferable in the underground spaces, with the aim to enrich and to develop new possibilities for the city. The paper present in this number of Trasporti & Cultura analyse some of the main factors in the building of urban underground spaces identifying another way to enrich the concept of smart (or intelligent) city. In fact, if we think that a smart city is the side where are concentrated innovation and urban vitality, it is possible to say that also the underground spaces can actively to contribute to this new image of the city.