Automatic rotation and zooming in mobile roadmaps

The aim of this research was to explore the navigational effects of two common features in current mobile roadmap systems: automatic rotation based on the vehicle's direction of movement and speed-dependent automatic zooming. 12 subjects tried four different visualization techniques for a mobile map in real traffic: no rotation/constant zooming, no rotation/automatic zooming, automatic rotation/constant zooming, and automatic rotation/automatic zooming. The subjects rated the techniques on four scales: position knowledge support, direction knowledge support, identification of real-world objects based on map objects and an overall score. The results showed that conditions involving automatic rotation and/or zooming got systematically more positive ratings on all scales than the conditions without those features. The implementation of automatic zooming created for this experiment was rated as very close to optimal. These results suggest that both automatic rotation and automatic zooming can enhance navigation when implemented to a mobile roadmap.