The Landmark Spider: Weaving the Landmark Web

Landmarks play an important role when humans navigate through foreign environments (Lynch, 1960; May, Ross, Bayer, and Tarkiainen, 2003). For example, trying to find the way is much easier if the navigator can rely on a description of the route based on well-recognizable objects in the environment, instead of navigating solely on the basis of street names and metric directions (Tom, and Denis, 2003). Therefore, collecting and incorporating landmarks along a route is a crucial task of pedestrian navigation systems that aim at providing efficient and reliable route instructions. Several proposals have been made on how to automatically extract landmarks from data sets and how such landmarks could be used to enhance wayfinding instructions for pedestrians (Elias, 2003; Nothegger, 2003; Raubal, and Winter, 2002). So far, however, the questions what landmarks to consider and how to integrate them in the route generation process is only poorly understood. We propose a landmark spider that assesses the relevance of landmarks along a route, includes these landmarks in the route generation process, and weaves a web of landmarks along that route.