Cities Untangled: Uncovering Order in Arterial Skeletons of Road Maps

Survey knowledge, as embodied in the road map, has been seen as too slow a navigational aid to function effectively at the speed of life in the smartphone/GPS-app era, capturing as it does details of the highway network that are seen to present too heavy a cognitive load to the user. Yet this very richness offers the promise of enabling the user to navigate with understanding, providing for exible and resilient trip planning. But what if the map’s heavy cognitive load was not because of the difficulty in dealing with its heavy load of information, but because that information was unnecessarily disordered? We suggest a comprehensible ordering has always existed within complex-appearing road maps. We propose a model for making this ordering explicit, highlighting a “skeleton” of arterials so as to appear visually untangled. The concept of the Use-Access Island (UAI), a bounded area with a coordinate axis-like array of spanning arteries, is introduced. As ever-finer meshes of these areas are highlighted across a street map, a hierarchy of visually untangled arteries can be rendered. Locations and routings can then be visualized in terms of nested sequences of “untangled” routings. When married to geographical designations, this iterative UAI schematization is designed to embody routing spatial knowledge. Is such an untangled map fast enough? We invite researchers to test the model. 1998 ACM Subject Classification H.5.2 User Interfaces