The Legibility and Permeability of Cities: Examining the Role of Spatial Data and Metrics

It has been long recognised that the underlying spatial structure plays an important role when navigating in urban environments. However, the modelling of the forms and properties that emerge from the city is still a difficult issue to address. The objective of the research developed in this paper is to study and represent two important qualities of urban environments as identified by Lynch and Bentley in their respective seminal works, that is, legibility and permeability. Our objective is to identify and implement a series of metrics applied to the layout of a given city that reflects these concepts of legibility, and then to evaluate to which degree these measures are correlated to different human perceptions of the city, particularly differences between humans who have or have not had an experience of a given urban environment. The whole approach is applied to the context of a neighbourhood of the city of Tehran in Iran. The findings show that permeability match relatively well with residents’ evaluations while legibility rather complies with newcomers’ evaluations.