زیرساخت‌های حمل ونقل و منظر شهری

The contemporary city presents itself more and more as a dispersed and fragmented organism inside which infrastructures, specifically transportation networks, cover a strategic role in moving people and goods; a mobility that has become an integrating part of society and one of the founding elements of contemporary urbanism. Moreover mobility, the set of fluxes, of persons and goods, material and immaterial, has become a founding element of contemporary urbanity and an organizing principle of our society. It guarantees access to goods and services, it guarantees the springing-up and strengthening of social relations, it represents the inexorable condition for economic development. In its becoming an inalienable condition for liberty of man, in contemporary society it represents something more than a mere functional need. It also no more sees only commuter traffic on pre-arranged routes, but articulates in trajectories with constantly changing destinations following unpredictable fluxes and directions. Such elements, taken together, demand a rethinking of the ways to conceive what up to only a few years ago was an exclusively technical space. They pretend a greater articulation of design solutions in order to give responses to the type of flux, trying to confer to the abstract space of mobility new figurations, new identities and a sense of meaning. Often the construction of these infrastructures, where accessibility-related questions are privileged and size is relevant, has a devastating and dividing effect on the surrounding territory, opening the way to urban and suburban decay. Since it implies a complex series of issues tied both to regeneration of urban patterns and to a broader process of land transformation, in this scenario infrastructure design cannot be taken as a mere technical item. Nowadays a crucial point for a sustainable urban development is given by shaping infrastructure so that this is able to integrate with the complex layering of the landscapes that they cross and to conceive it as a fundamental element in the process of regenerating urban environment. Among contemporary infrastructures, the road network with its numerous lanes and intersections to other grids of the network is, spatially, the potentially most invasive one. It is also essential to the life of the city. In time it has always organized territory and built urban space. In its connecting more or less distant points – longitudinal connectivity – it organizes and structures a cradle of variable dimensions at its margins. A series of elements link to these margins ensuring, or not, transversal connectivity. The spatial and figurative quality of this cradle and its capacity to connect is crucial for the social use of the street. The endless search for greater speed and fluid traffic fluxes, wanting to define longitudinal connections evermore efficient, brought to the construction of a series of high speed axes that, in enhancing speed, reduced links to the overall network, thus to transversal connectivity. The result is an evident detachment of the street from crossed territories, a detachment that caused in some cases a strong cut within urban systems, the generation of many unresolved spaces and a reduction, if not the complete cancellation, of the social value of the street. After years in which infrastructure design was distant from the form of the city, today a series of experimental project are bringing to light the high potentials of infrastructure design in improving quality of life in functional, social and aesthetic terms. In Europe the construction of infrastructural corridors, airports and high speed train stations, imposed transformations both at a urban and territorial scale; this can represent a great opportunity to reorganize and regenerate many unresolved spaces. Furthermore, many cities have to deal with a series of high speed motorways badly absorbed by the forma urbis because they were built without taking care of urban measure and rhythm. They need to be reintegrated through a new strategic thinking and the inventive capacity of architects. The potential of multi-level infrastructures reconciling high speed travelling and the civic value of the street are experimented by Arriola e Fiol in the design for Gran via the Llevant in Barcelona while the research entitled “The design of the connection of the GRA in Rome to urban networks”, conducted by Department of Architecture (Sapienza University of Rome) inquires the strategies to redefine a motorway into an urban boulevard. Moreover nowadays several projects are investigating the possibility to reformulate a new and contemporary solution of inhabited bridges looking for a mix of functions and activities. And finally in the regeneration of contemporary overcrowded city a real challenge is to conceive the construction of the subway as an element of an urban regeneration programme. Some subway stations opportunely selected, in relation with their strategic location, may be a simple crossing point with functional meaning, or it may be a junction exchange of some complexity, or a reference point for an urban design project, able to associate transport and authentic public space.