This paper disentangles cognitive and communicative factors influencing planning strategies in the everyday task of choosing a route to a familiar location. Describing the way for a stranger in town calls for fundamentally different cognitive processes and strategies than actually walking to a destination. In a series of experiments, this paper addresses route choices, planning processes, and description strategies in a familiar urban environment when asked to walk to a goal location, to describe a route for oneself, or to describe a route for an addressee. Results show systematic differences in the chosen routes with respect to efficiency, number of turns and streets, and street size. The analysis of verbal data provides consistent further insights concerning the nature of the underlying cognitive processes. Actual route navigation is predominantly "direction-based" and characterized by incremental perception-based optimization processes. In contrast, in-advance route descriptions draw on memory resources to a higher degree and accordingly rely more on salient "graph-based" structures, and they are affected by concerns of communicability. The results are consistent with the assumption that strategy choice follows a principle of cognitive economy that is highly adaptive to the degree of perceptual information available for the task. (Contains 3 tables and 8 figures.)