Abstract
The effects of alternative navigation device display features on drivers' visual sampling efficiency while searching forpoints of interest were studied in two driving simulation experiments with 40 participants. Given that the number of display items was sufficient, display features that facilitate resumption of visual search following interruptions were expected to lead to more consistent in-vehicle glance durations. As predicted, compared with a grid-style menu, searching information in a list-style menu while driving led to smaller variance in durations of in-vehicle glances, in particular with nine item displays. Kinetic touch screen scrolling induced a greater number of very short in-vehicle glances than scrolling with arrow buttons. The touch screen functionality did not significantly diminish the negative effects of the grid-menu compared with physical controls with list-style menus. The findings suggest that resumability of self-paced, in-vehicle visual search tasks could be assessed with the measures of variance of in-vehicle glance duration distributions.
Statement of Relevance: The reported research reveals display design factors affecting safety-relevant variability of in-vehicle glance durations and provides a theoretical framework for explaining the effects. The research can have a significant methodical value for driver distraction research and practical value for the design and testing of in-vehicle user interfaces.
Acknowledgements
The authors want to express their gratitude especially to Mikko Nirhamo at Nokia for his valuable collaboration. Wealso want to thank the two anonymous reviewers for providing helpful and constructive comments and thus helping us to significantly improve the quality of the paper. This work was supported by Theseus, a research collaboration project on human-technology interaction funded by TEKES (Finnish Funding Agency for Technology and Innovation). The driving simulation environment was developed by a grant from the Henry Ford Foundation.