Distance is a most dominant factor affecting the decision to walk in cities, as people usually seek to minimize the duration of walks, particularly when they aim to reach a destination. Similarly, subjective overestimation of distance was found to have a reducing effect on walking behavior. Hence, understanding the relations between walkability and cognitive distance has special significance for planning walkable environments and promoting pedestrian activity. The urban scale is a unique case of distance knowledge since it is acquired through actual body movement and direct perception of the immediate surroundings.
Cognitive distance is affected by external conditions and properties of the built environment, as well as individual and social aspects. It is also sensitive to systematic distortions that result from cognitive heuristics and biases. Due to all these and more, cognitive distances rarely reflect the objective distances measured in the actual environment.  
The study of cognitive distance, however, presents some major challenges that are typical to the study of any subjective phenomena. What has been done, how it was carried out, and what has been found so far? What should be reconsidered and how can we improve our understanding of this complex reciprocity between people and their built environment? In this talk I will bring a brief review of that field investigation and its outcomes thus far.