Cell phone use more distracting to drivers than chatting with passengers

When it comes to driving, not all conversations are alike.
A study published in December 2008 by psychologists at
the University of Utah found that drivers talking on cell
phones made signifi cantly more driving errors than those
who talked in person to passengers.

The researchers paired 41 drivers with friends. Participants
ranged in age from 18 to 49, but most were young
(the average age was 20), with men and women about
equally represented. During each of three experimental
conditions, one member of the pair was randomly chosen
to be the driver and the other was designated the partner.
During each experiment, the driver operated a driving
simulator that not only mimicked actual traffi c conditions
but also measured aspects of driving performance.

In the first experiment, the driver used a hands-free
cell phone to talk with the conversation partner, who was
located elsewhere. In the second experiment, the driver
and passenger talked while seated next to each other in
the driving simulator. In the third experiment, the two sat
next to one another but did not talk.

Drivers holding conversations by cell phone were four
times as likely to miss pulling off at a rest area (as previously
instructed) as those talking to passengers in person.
Th e cell phone users were also more likely than the others
to drift in their lanes and to keep more distance between
their cars and those in front of them.

The researchers speculate that driving while talking on
a cell phone may make it harder for someone to process
external information and concentrate on driving conditions—
a condition they termed “inattention blindness.”

Drews F.A., et al. “Passenger and Cell Phone Conversations in Simulated
Driving,” Journal of Experimental Psychology: Applied (Dec. 15,
2008), Vol. 14, No. 4 (in press).