New cars today can make phone calls for you and probably even pay your bills all by the sound of your voice. But in a groundbreaking new study, AAA shows hands-free isn’t risk free, and implores auto manufacturers to consider safety before installing new and smarter gadgets.
In 2011, the AAA Foundation for Traffic Safety set out to study whether hands-free devices actually reduce the risk of driver distraction.
Drivers can be distracted in three primary ways:
- Visual distraction (eyes off the road)
- Manual distraction (hands off the wheel)
- Cognitive distraction (mind off the task)
Texting is so dangerous because it requires a driver to use his or her eyes, hands, and mind. But what about tasks that use the mind alone? AAA put study subjects in a lab, a driving simulator, and an instrumental vehicle to test how they fared while talking and listening. Measures used to assess the cognitive impact included brake reaction time and following distance; reaction time and accuracy to a peripheral light detection test; brainwave (EEG) activity; and, eye and head movements.
The findings were striking. Engaging in activities that distracted the mind from driving impaired drivers in the following ways:
- Increased reaction time
- Missed cues and decreased accuracy (to peripheral detection test)
- Decreased visual scanning
- Suppressed brain activity in the areas needed for safe driving.
The study ranked the six distracting activities tested, according to the amount of cognitive workload required. The order, from lowest amount of distraction to highest, according to amount of cognitive workload, was:
- Listening to the radio – 1.2
- Listening to an audio book – 1.8
- Hands-free cell phone call – 2.3
- Conversation with a passenger – 2.3
- Hand-held cell phone call – 2.5
- Speech to text system – 3.1
Source: AAA Measuring Cognitive Distraction in the Automobile – 2013
The study makes clear that passive listening, to the radio and audio books, provides some cognitive distraction, but not at the level of interactive conversations – this includes the lo-tech distraction of talking to passengers. Driver interactions with the new in-vehicle speech-to-text systems provided the highest level of distraction.