Conversing 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 (NSC) 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 phone conversations.

"This study adds new data to the ongoing national debate on driver distractions and their causes," said Alan C. McMillan, NSC President, "and 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," McMillan said, "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."

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 dialing a phone. The scientists concluded that it was the active engagement in a conversation that caused the higher levels of driver distraction.

The issue of driver distractions caused by cellular phones becomes increasingly important as cell phone use becomes more prevalent in American life.

According to studies conducted by the National Highway Traffic Safety Administration (NHTSA), some form of driver distraction is a contributing factor in 20 to 30 percent of all crashes.

The Cellular Telecommunications and Internet Association estimates that there are currently 120.1 million cellular phones in operation in the United States, and a recent NHTSA survey found that nearly 75 percent of drivers reported using their phone while driving.

A NHTSA observational study released last month estimated that 500,000 drivers of passenger vehicles (cars, vans, sport utility vehicles and pickups) are talking on hand-held cell phones during any given daytime moment throughout the week.

In a "Multitasking Statement" adopted by NSC in March of this year, the council noted that "a driver''s first responsibility is the safe operation of the vehicle" and that "best practice is to not use electronic devices including cell phones while driving." (The statement can be found on NSC''s Web site at www.nsc.org/news/policy/multitasking.htm).

by Virginia Foran