Crash data from the National Highway Traffic Safety Administration (NHTSA) indicate that approximately 25% of all crashes are the result of inattention or distraction. This article reports on a study that delved further into the distraction factor by exploring task performance under conditions in which attention is switched back and forth between two tasks. The authors investigated the effects of interruption timing, type of interruption, and age, on task time and primary task resumption time, under conditions in which attention was switched back and forth between two tasks. This design was meant to replicate the situation when drivers shift attention between attending to the road and to an in-vehicle task. Results showed that the timing of interruptions had a significant impact on task resumption times, indicating that the most costly time to interrupt task performance is during the middle of a task. However, this effect was overshadowed by age-related performance decrements for older participants. The authors conclude with a brief discussion of the implications of this research for the current of in-vehicle devices.
Abstract