This contribution synthetically presents the results of the first stage of a research finalized to look into the architectural individuality of San Luca portico in Bologna; an extraordinary extraurban arcade - system, a strong sign of the urban development of the city in the seventeenth and eighteenth century stable in the urban image of Bologna.

The team has developed this research with the aim to achieve a deeper knowledge of the portico, trying to understand its environmental and architectural characters, how it has been formed and transforrned, the exigency architecture, the connections within the surrounding urban texture and the landscape, and attaining to find out its symbolic and existencial value for the city.
The existing studies about the portico are mainly historic, or somehow circumstantial to some traits of the arcades. They allow only a partial reading which does not permit to completely understand its identity. On the contrary, this research exhibits a complete and systematic graphic documentation of the portico as a whole. It should allow various levels of reading of the reality, describing San Luca portico and the remarkable urban system that originated from it under different perspectives, maintaining the original features of route and “sacred” road.

The strength of the representation is to let stand out and make clear, in a synthetic and immediate way, otherwise hidden relations, and also to relate its history and events with great efficacy. The aim is not to determine a lasting image of the city. It is to represent the traces of the events and of the transformations of the places when they become urban, determining the results of different drawings to describe its continuous evolving in time.

Moreover, the secondary aim of the work has been outlined: to look into the urban shape settled and led by the portico. More generally, how an important urban feature of Bologna was formed and developed. The evocative historical views, which decorate the portico and its urban contest, witness an urban landscape that drastically changed because of the building of the portico, with particular reference to these last years; nevertheless, while the plan tract is almost entirely comprised in the urban texture, the one on the hill represents a marked and distinct sign which hails people coming to Bologna from north and from west.

Given the above stated presuppositions, the traditional representation in parts or detached pictures is preliminarily excluded.
The whole survey is based both on photographic, archivistic and historical documentations and on direct and indirect measurements. Mappings have been carried out by students at the second year of the Faculty of Engineering – University of Bologna. The strict procedural constraints and the explicit graphical methodology has allowed to merge every single mapping in one comprehensive document. Its graphic language has been specifically designed coding iconographic signs. The whole fronts have been surveyed with direct methods, manual and at sight ones, integrated with photographic correction methods according to the use; sections have been executed with direct measuring methods and the same with reference to the survey of the ground floor.
The result is a long “drawing” about 25 meters in length (if 1:200), a “ribbon” where the drawings of the parts are reset through the connection of the plant of the portico, from the longitudinal section and from the view of the urban fronts.