“ Cross the River and Then Follow the Tracks ”: Overview Information on the Way to Take

Wayfinding support is an important application of mobile systems and often an (integral) part of location based services (LBS). If needed, these systems may offer their users information on getting to a specific destination. Usually, these instructions are given incrementally, i.e. only the next decision due is communicated to the user. Thus, such systems do not offer any survey information; users get no idea on what to expect along their trip. To reduce this limiting dependency and to be able to cope for potential system's failures, users should be provided with an overview on the route to take. In this paper, we present work in progress on an approach to generate this overview information. It provides in-advance information on the crucial parts of a route—the major reorientation points. The presented methods are based on our model for context-specific route directions: the generation process results in an abstract relational specification of the instructions reflecting conceptual elements of route information, which may then be externalized in different modalities. We argue that presenting overview information on a route that concentrates on the relevant reorientation points enhances navigation systems without distracting a user with unnecessary detail.