Applying bifocal displays to topological maps

Presentation techniques for topological networks can be broadly classified as distortion‐oriented and nondistortion‐oriented. Although there has been a growing interest in applying various distortion‐oriented techniques, the application of an earlier example, the bifocal display, has so far been underexploited. This article describes a number of human‐computer interface techniques potentially relevant to the presentation and navigation of topological networks associated with transport systems, and describes a preliminary experimental study of a number of techniques for presenting the London Underground map as part of a real‐time information system for travelers.