MODELLING URBAN ROAD NETWORKS INTEGRATING MULTIPLE REPRESENTATIONS OF COMPLEX ROAD AND JUNCTION STRUCTURES
Necla Uluğtekin, Ahmet Özgür Doğru, R. C. Thomson · 2004
Generalization is certainly one of the most important current issues in cartography, with particular emphasis being placed on its automation. This paper considers the automation of generalization applied to road networks- primarily urban roads. The user context for this study is car navigation, which entails such activities as route planning, the recognition of locations and landmarks on a route, and the negotiation of complex junctions. As noted by Timpf et al. (1992), these activities require data at a wide range of scales and at different levels of abstraction. Key problem areas for navigation are those parts of the network where a change in topology occurs with a change in scale. A divided highway with a two-line representation will be represented by a single line at a sufficiently small scale and, with continued scale change, may even be completely eliminated. Such changes can be expected to produce many problems to the navigating user, and hence to the cartographer. Fundamentals of multiple representational databases are developed for the urban road data, where the significant transformations in junctions and roadways are identified and tracked. Tools for formalizing and handling multi-scale representations are presented.