The immediate context of this book is the changing theoretical debate within and around mobility. After decades of stagnation into quantitative problem-solving approaches and models of functional organisation the discourse on mobility is now taking its moves - once again - from within the fields of urban design and architecture. However, although there is a growing awareness that mobility is part of the changing perspective towards the built environment, there is still a great deal to do. As Jonathan Bell affirms “we have reached an impasse. Society is torn; economically bound to buy, use and maintain our cars, yet environmentally minded to cut back, hold off and conserve. Roads and cars generate even stronger passions. Can these conflicts be resolved?” (2001: 118). This book discusses the possibility to unravel the conflicts by looking at the source that generates them. Namely, the lacking cooperation among disciplinary fields in charge of the planning and design of the spaces of mobility, and the consequent crumbling of the design knowledge crucial to foster a better integration of roads as infrastructures within the city. It questions the mechanisms underlying the problems of contemporary spaces of mobility and the ways urbanism and architecture have contributed together with transportation and traffic engineering to produce the functional, spatial and aesthetic poverty of such products. Therefore the aim of this book is not to solve the impasse by providing the magic formula for the enduring car-city conflict, but to offer some directions to develop a shared domain theory for urbanism, mobility and architecture. In doing so, this book poses a challenge to a traditional convention of mobility as solely concerned with traffic and transportation, urbanism as solely involved with city planning and design, and architecture as solely related to with the production of artefacts. It presents a paradigm that extends across disciplines to support the design of everyday urban spaces. At its most basic level, it allows us to speak about the possibility to reweave our disciplinary fields, at the intersection of theory and design practice. The basic premise underlying this research is that the spaces of mobility in contemporary cities ask for an integrated approach that can no longer be delayed. Despite the subsequent promises of architecture and urbanism all through the 20th century, the spaces of mobility are still confined to a separate treatment, which tends to leave to the transport and traffic experts the physical definition of their function and location in specialised enclaves. Previous studies have focused, with very few exceptions, on the heroic feats and structures that enhance the speed and drama of automobile travel, as well as facilitate their production and integration in our cities; the story of the modern factory, multi-storey car park, bypass scheme and modernist city plan. However, increasingly unfashionable and controversial, the age of the six-lane solution to traffic congestion is slowly being consigned to planning history, a misguided approach that has resulted in as many problems as it solved. Just compare our current negativity with the automotive optimism of the past. Besides, previous researches have overlooked one significant aspect of mobility that is the progressive disentanglement of urban design and architecture from technical knowledge. Urban designers and architects have lost their ability to create a fruitful cooperation with each other, as well as with other disciplines - especially with transportation and traffic engineering. By this, our professions also lost their ability to understand and foremost to design the spaces of mobility as an integrated part of the built environment. The first hypothesis that this research follows is that this loss corresponds to an important shift in the way practitioners act nowadays. Today urbanism operates in a continuous present. It is a process wherein the outcome, the tangible results remain unpredictable till the last moment. Besides, the geographic scale and the fundamental nature of civil engineering interventions challenge the progressive marginalization of urbanism and architecture. Modernism - rather, its best-known and schematic aspects - had theorized the independence of the road from the urban context, ascribing to the landscape the connecting role between the two systems. This principle, though, supports an intrinsic contradiction. On the one hand, the road is recognized as the new ordering principle not only for specific buildings on a given site, but to construct the site itself; on the other, the road is declassified from material practice to architectural decoration, in the sense that the ‘new role’ of the road as regulator of the modern city and its landscapes has never been specified in terms of design knowledge and technique. Although back in the 1960s some members of the TEAM X turned against the postulations of the Athens Charter (1933), a profound critical analysis of the functionalist tradition - especially of the directions and symbols of modernization - across the disciplines did not yet take place. These directions and symbols of modernization might be summarised as: first, the increase in scale of development urban projects; second, the status of infrastructure, which has changed from a self-sufficient service element to the most visible evidence of the city as network and an attractor of overlapping activities; and third, the increase in car ownership, especially in Europe, that has brought a change of perspective of the contemporary city and its dynamics. As Alex Wall argues “the abandonment by architects of these issues led to the unnerving spectacle of a polarized ideological struggle: the idea of the city of motorways versus the idea of the city of cut stone” (1996: 159). It is precisely ‘the unnerving spectacle of a polarized ideological struggle’ that is here under discussion. For several decades the debate around mobility and related infrastructures has been centred on the themes of the car and urban sprawl. Without denying that the car has inverted our perception of urbanism in many ways and determined its crises, the failure of the integrated urban design project for mobility is due to other factors as well. The most important one is that for too long the themes of mobility inhabited the urban design and architectural project only as a theoretical premise. In the sense that projects on and around mobility have been not sufficiently expert to interpret the increasing complexity of mutational processes characterising physical infrastructures, and at the same time to become operational in the changing territory. Nevertheless, the sustainable development of mobility continues to be a primary task in spatial planning. There is a growing awareness that transportation systems, which will stand to the demands of the future, must be conceived, planned and evaluated according to a set of multiple variables. Once established, they have to be reconsidered and optimised regularly to fit the evolution of the demand and the city development. Because of these facts, the task involving infrastructure design is presently subject to great debate. The traditional approaches to infrastructure planning and design, which rely on decision-making based solely on functional and financial considerations is currently being strongly disputed. As a matter of fact, internationally there is a fairly general consensus about the need to tackle mobility from an integral point of view. What motivates this need is not only the complex nature of the planning and design task itself, but also the huge investments required to develop such infrastructures or to ‘re-integrate’ existing ones. So far urbanists and architects played a rather marginal role in the processes of infrastructure planning and design. Nowadays this situation is changing and designers – especially in The Netherlands – are offered more opportunities to participate actively in the design of the spaces of mobility. However, urban designers and architects run a risk if they allow themselves to be drawn into these kind of processes without having a clear professional role and a clear content to offer. As many projects in real practice teach us, clearly defined ambitions can become subordinated - in the design - to uninspired opportunism. This brings us to define the second research hypothesis: that it is necessary to re-define more clearly the role of designers within these processes. By doing so this book is questioning the legitimacy of the current situation, specifically if this is a missed opportunity, which reflects a hiatus in design knowledge. The third hypothesis therefore is that there is above all the urgent need to give content to that knowledge, as designing for mobility is giving form to urban culture. However, the gap between disciplines and design cultures in appreciating the richness of meaning of road infrastructure is historically so wide that it is exceptionally complex to find answers all at once. This research looks therefore, for readjustment rules, settlement logics that are much more empirical, specific and limited then they were described in the past. It searches for ways to reinstate a positive morphological value to technical intervention, to reflect on the ordering role of road infrastructure within the networks, learning from tradition in the attempt to retrieve it as a component of the urban form. In order to do so it is above all necessary, with respect for the specific competences, to begin by restoring the road - and the spaces of mobility more in general - to the realms of urban design and architecture. Urbanists and architects have therefore an important task ahead. As Ignasi de Solà-Morales argues “to design mutation, to introduce oneself into its centrifugal energy, ought to involve at once design of the public and private space, of mobility and of specialised sites, of the organism as a whole and of the individual elements” (1996: 14). This means that in order to develop integrated projects for the sustainable development of the built environment, urbanists and architects ought to enlarge their ‘working field’ to the so-called technical professions by constructing a common ground, by breaking down disciplinary barriers and by approaching mobility as a new cross-disciplinary domain.