Cognitive Distraction Study Suggests SMS Text Messaging Systems May Adversely Affect Traffic Safety
Researchers designed three experiments. In each, drivers were asked to perform 8 different tasks, ranging from driving without any distraction to driving while taking what is called an Operation Span (OSPAN), a test specifically designed to measure a person's ability to multi-task. In the first experiment, subjects drove a car. In the second experiment, subjects drove a driving simulator. In the third experiment, subjects drove an instrumented vehicle in a residential neighborhood. For each task in each experiment, researchers assessed driver mental workload, reaction time, and accuracy.
With non-distracted driving and driving while taking an OSPAN representing the best-case and worst-case distractions, the study determined that listening to the radio or an audio book produced low levels of cognitive driving distraction. Talking to a fellow passenger or on a hand-held or hands-free cell phone produced moderate levels of cognitive driving distraction. Performing in-vehicle activities, such as using a speech-to-text messaging system to send or receive text messages, produced high levels of cognitive driving distraction.
The AAA Foundation for Traffic Safety summarized the findings: "Compared to the other activities studies, we found that interacting with the speech-to-text system was the most cognitively distracting. This clearly suggests that the adoption of voice-based systems in the vehicle may have unintended consequences that adversely affect traffic safety."