Cognitive Workload while Driving and Talking on a Cellular Phone or to a Passenger

Abstract

Twelve adults experienced in using cellular telephones participated in an investigation of driving and performing a communication task. They navigated a closed serpentine driving course, requiring constant driving activity. Their communication task was responding to a verbal cognitive test battery administered by the passenger or via cellular telephone. The test battery consisted of sentence remembering with read-back and verbal puzzle solving. Baseline treatments were navigating the course without communication and responding to the test battery while parked. Subjects were prompted to report their current level of workload, using the Subjective Workload Assessment Technique (SWAT), throughout their tasks. Driving speeds were significantly lower when using the phone than they were with the passenger speaking, but the analysis did not reveal a difference in perceived workload between these conditions. Workload ratings were lower in the drive-only condition than they were when the driver used the phone.