Effects of a Voice Interface on Mirror Check Decrements in Older and Younger Multitasking Drivers

Older drivers comprise an undue percentage of roadway crashes and fatalities, and existing data implicates decrements to situational awareness as one factor. Although forward attention in older drivers is well studied, rearward attention for this population is little explored. What evidence exists has suggested reduced mirror checks, especially under conditions of multitasking. Voice-enabled in-vehicle systems may represent a partial solution, requiring fewer resources and freeing drivers for behavior which maintains better rearward attention. The present study asked participants to drive on a highway in an instrumented vehicle under conditions of baseline driving, manual radio tuning, and radio tuning assisted by a voice-enabled interface. Results indicate that multitasking greatly reduced mirror checks for all groups. Older participants devoted a greater amount of time to mirror checks than younger participants when just driving, but dropped to levels similar to younger drivers while multitasking. Voice-enabled radio tuning was associated with reduced decrements in mirror checks for all age groups. Discussion centers around this new understanding of differing attentional patterns across lifespan, as well as the impact of voice-enabled interface.