on cell phones while driving can lead to significant decreases in driving performance,
according to a new study reported in the August/September 2001 issue of the
National Safety Council’s Injury Insights.
The study found that driver distractions due to cell phones can occur regardless
of whether hand-held or hands-free cell phones are used, and that cell phone
conversations create much higher levels of driver distractions than listening
to the radio or audio books.
According to the study’s authors, the findings suggest that legislative initiatives
that restrict hand-held devices, but permit hands-free devices, in motor vehicles
are not likely to significantly reduce driver distractions associated with cell
“This study adds new data to the ongoing national debate on driver distractions
and their causes,” said the president of The National Safety Council, Alan
“It underscores the importance of reiterating that a driver’s primary
obligation is to operate his or her motor vehicle safely.
“A great deal more research like this is needed to help us fully understand
the public policy implications of the growing use of cell phones and other electronic
devices – such as global positioning systems, faxes and computers –
in moving vehicles,” McMillan said.
The research was conducted by David Strayer, Frank Drews, Robert Albert and
William Johnston at the University of Utah.
The study used 64 participants in controlled, simulated driving conditions.
The research participants were randomly assigned to listen and change radio
stations, listen to audio books, engage in conversations while holding cell
phones, and engage in conversations using hands-free cell phones.
The subjects were presented with a series of driving tasks, such as braking
for red lights, and their responsiveness and reaction time to these driving
tasks were measured.
The study found that the subjects involved in phone conversations showed significantly
slower responses to traffic signals and missed signals entirely much more often
than subjects who were listening to the radio or a book on tape.
There was no measurable difference, however, in driver responses among those
subjects using hand-held phones and those using hands-free devices.
According to the authors, this indicates that the loss of responsiveness motorists
experience while using cell phones is not due solely to holding or dialling
The scientists concluded that it was the active engagement in a conversation
that caused the higher levels of driver distraction.