The prevailing wisdom has been that using cell phones while driving was dangerous unless you used a hands-free device. In that vein, a whole slew of devices have been installed in vehicles that allow for hands-free/voice-activated operation, including GPS.
But a new study from the AAA Foundation for Traffic Safety undercuts that presumption and demonstrates that use of hands-free devices doesn’t make cell phone use behind the wheel any safer. (A point also made in this infographic.)
The study (this fact sheet has the highlights) starts from the foundation that there are three main sources of driver distraction:
- Visual (eyes off the road)
- Manual (hands off the wheel)
- Cognitive (mind off the task).
Studying cognitive distractions has been a challenge. The goal of the AAA study was to:
- Isolate the cognitive elements of distracted driving;
- Evaluate the amount of cognitive workload caused by various tasks performed by drivers; and
- Rank tasks according to how much cognitive distraction they cause.
The researchers conducted three types of experiments, measuring:
- Subjective workload ratings
- Brake reaction time
- Following distance
- Brainwave activity
- Eye and head movements
- Reaction time and accuracy to peripheral light detection test.
In each experiment, they analyzed six common driver tasks:
- Listening to the radio
- Listening to an audiobook
- Talking with a passenger
- Talking on a handheld phone
- Talking on a hands-free phone
- Using a speech-to-text email system.
The study found that even when a driver’s eyes are on the road and hands are on the wheel, sources of cognitive distraction cause significant impairments to driving, such as:
- Suppressed brain activity in the areas needed for safe driving;
- Increased reaction time;
- Missed cues and decreased accuracy; and
- Decreased visual scanning of the driving environment (think tunnel vision).
The worst culprit—driver interactions with in-vehicle speech-to-text systems—which are offered in many new vehicles—create the highest level of cognitive distraction among the tasks assessed.
Bottom line: Hands-free doesn’t mean risk free.
So ensure that you have a comprehensive cell phone use policy that bars the use of hand-free devices and requires workers to pull off to the side of the road if they need to use their cell phone while driving.
Go the OHS Insider’s Cell Phone and Other Electronic Devices Compliance Centre for additional resources, including:
- a slideshow on 11 lawsuits involving worker distracted driving
- the dangers of texting while driving
- a briefing for senior management on company liability for distracted driving accidents
- a Music Device Policy
- a Distracted Driving Infographic.