ARTICLE
Why Hands-Free Doesn’t Work
In 2009, Webster’s Dictionary selected “Distracted Driving” as its Word of the Year because of its prevalence in
our cultural lexicon. Unfortunately it is a much used and needed term. Distracted driving is driving while turning
our attention to non-driving related tasks like phone conversations, texting, adjusting the GPS or vehicle stereo
or even surfing the web. We sometimes view this behavior as positive, making the most of our time by
multitasking. These distractions, especially cell phones, are a safety hazard because they disrupt a driver’s
concentration in three ways:

Visual distraction- the driver’s eyes are taken off the road to dial, answer or text.

Mechanical distraction- quite simply, by having a phone in hand, the driver only has one hand on the
wheel.

Cognitive distraction- the driver’s mind is off the most important task of driving while dealing with the
phone.
To help reduce this hazard, all states have adopted laws that prohibit cell phone use while driving without the
use of a hands-free device like a Bluetooth or a vehicle’s built-in system. Although this is a good idea in theory,
it doesn’t work because of the way that the human brain is set up and the three ways that cell phone use
distracts a driver. Although a hands-free device may eliminate a driver’s visual and mechanical distractions, the
cognitive distraction remains.
When someone performs any two tasks at the same time, one becomes the primary task, which receives the
brain’s main focus and the other is the secondary task, receiving less than the brain’s main focus. The brain is
able to switch between tasks and the tasks can be shifted from primary to secondary and back again. The
bottom line is that humans cannot perform two attention demanding tasks, like driving and talking on a cell
phone, well.
This statement has been explained by a study done on the human brain at Carnegie Mellon University. Specific
sections or lobes of the brain are tasked with dealing with different aspects of our everyday life. There is a
section that is responsible for the activities necessary for driving, another deals with listening and language
comprehension. When trying to do these two cognitively complex tasks at the same time, the area of the brain
associated with driving was found to be less active. This is because of a “Bottleneck” in the brain; when
different regions of the brain must pull from a shared and limited resource (brain function) in order to complete
unrelated tasks.
This bottleneck results in Inattention Blindness. While driving, we receive the majority of the information we
need through our visual sense. Drivers using hands-free cell phones have the tendency to look at, but not
really see objects. The National Safety Council (NSC) estimates that drivers using cell phones, even handsfree, fail to see up to 50% of the information in their driving environment. The cognitive distractions caused by
the cell phone causes less attention to the driver’s visual surroundings so that all of the information the driver
sees is not processed and stored by the brain.
ARTICLE
Why Hands-Free Doesn’t Work
Because of this, hands-free drivers are less likely to see:

High and low relevant objects, causing an inability to allocate the appropriate amount of attention to the
most important information

Visual cues necessary to their safety and navigation of their vehicles

Exits, red lights and stop signs

Navigational signs bearing route numbers or street names

The content of objects like billboards
Inattention blindness causes a driver to miss important events in the driving environment. These missed events
can make it impossible for a driver to execute a safe response to a hazard like steering around something or
braking to avoid a rear end collision. These issues are exacerbated when using hands-free devices because
they are purported to make cell phone use while driving safer which can give a driver using one a false sense of
control of the complex task of driving and using the cell phone.
A very logical question at this point would be; why don’t conversations with passengers or listening to music
have the same negative effects on driver concentration and ability. The NSC has found that adult passengers
actually actively assist drivers in being safe by helping to monitor and discussing traffic with the driver. A
passenger in a vehicle can see changes in traffic patterns and volume and limit their conversation at these
times. A caller is not able to see the driver’s environment and doesn’t know if it has become challenging so
they wouldn’t know to limit their conversation or end the call. Listening to low or moderate volume music does
not affect a driver’s visual attention so it is not seen to detract from the driver’s ability to drive safely.
Hopefully this information will lead states to rethink laws allowing hands-free cell phone use. Most studies show
little or no difference between accident rates of cell phone users, hands-free or otherwise, so the use of a
hands-free device can give drivers a false sense of safety while on the road.