Comparison of Visual-Manual and Voice Interaction With Contemporary Navigation System HMIs

Typically, driver interactions with in-vehicle devices such as navigation systems have been accomplished using a visual-manual interface. As a result of recent advances in technology, voice activated interfaces are being introduced, which reduce or eliminate the need for manual inputs and related visual scanning. This paper compares driver use of contemporary examples of the 2 different types of interface for several types of navigation destination entry tasks based on over-the-road evaluations. These data include glance behavior, HMI interactions (manual inputs, etc.), driver/vehicle response and performance including lane deviations, and subjective ratings. In general, the results show that, for a given task, the example contemporary voice activated systems result in fewer glances, shorter glance durations, fewer entry steps, improved driver/vehicle performance, and improved subjective ratings for ease of task accomplishment and mental workload.