The emergent interest in ontological and conceptual approaches to modeling route information results from new information technologies as well as from a multidisciplinary interest in spatial cognition. Linguistics investigates verbal route directions; cartography carries out research on route maps and on the information needs of map users; and computer science develops formal representations of routes with the aim to build new wayfinding applications. In concert with geomatics, ontologies of spatial domain knowledge are assembled while sensing technologies for location-aware wayfinding aids are developed simultaneously (e.g. cell phones, GPS-enabled devices or PDAs). These joint multidisciplinary efforts have enhanced cognitive approaches for route directions.In this article, we propose an interdisciplinary approach to modeling route information, the wayfinding choreme theory. Wayfinding choremes are mental conceptualizations of functional wayfinding and route direction elements. With the wayfinding choreme theory, we propose a formal treatment of (mental) conceptual route knowledge that is based on qualitative calculi and refined by behavioral experimental research. This contribution has three parts: First, we introduce the theory of wayfinding choremes. Second, we present term rewriting rules that are grounded in cognitive principles and can tailor route directions to different user requirements. Third, we exemplify various application scenarios for our approach.