New study shows drivers using cell phones twice as likely to cause rear-end collisions

Drivers talking on cell phones are nearly twice as likely as other drivers involved in crashes to have rear-end collisions, according to a new University of North Carolina at Chapel Hill study. Crashes involving cell phone use, however, are less likely to result in fatalities or serious injuries than crashes not involving the devices.

Almost 60 percent of licensed N.C. drivers have used a cell phone while behind the wheel, investigators from the UNC Highway Safety Research Center (HSRC) found. The most common violations for drivers involved in collisions while talking on phones were failure to reduce speed, traffic signal violations such as running red lights, speeding, following too closely and failing to yield to other vehicles.

“Not surprisingly, cell phone users were less likely than those who don’t have them to perceive talking while driving as a distraction or safety concern,” said Dr. Jane Stutts, associate director for social and behavioral research at HSRC. “They were also less supportive of legislation that would ban drivers’ use of cell phones or issue stricter penalties for cell phone users involved in crashes. However, three-fourths of both groups indicated they would support legislation prohibiting the use of hand-held phone by drivers, except for emergencies.”

Stutts’ study, “Cell Phone Use in NC: 2002 Update Report,” was sponsored by the NC Governor’s Highway Safety Program and is an extension of earlier work issued in November 2001.

Co-authors of the new report released today (March 26) are Dr. Herman Huang and William W. Hunter, research associate and associate director, respectively, at HSRC. Senior computer analyst Eric Rodgman helped with data gathering and analysis.

The investigation involved a statewide telephone survey of 500 cell phone users and 150 others to gauge driving-related behavior and opinions.

Also included were analyses of characteristics of cell phone-related crashes based on 452 such incidents found during a computerized search of N.C. crash report narratives from 1996 through August 2000. In addition, the N.C. State Highway Patrol collected more data for the study over two months last summer.

“We wanted to know how many people were talking on cell phones while driving and how many crashes were cell-phone related,” Stutts said. “We also wanted to find out more about these crashes.”

Based on the data collected, the researchers estimate that cell phones are responsible for at least 1,500 motor vehicle crashes across the state each year.

Other findings were that:

• Drivers most often talking on cell phones were between ages 25 and 39, and a higher proportion of users drove sport utility vehicles than non-users.
• The average time per day spent talking on phones while driving was 14.5 minutes, while the medium time was five minutes. Talk time decreased with increasing age and was higher among males than females.
• One in four users had a hands-free device although they did not always use it when talking.
• Cell phone crashes were more likely to occur during mid-day and afternoon hours in urban areas and on local streets.
• Most cell phone users were at least partially responsible for their crashes.

Investigators identified cell phone-related crashes by running computerized searches for collision reports in which officers specifically mentioned the telephones in their descriptions each crash, Stutts said.

The special two-month data collection effort by the N.C. Highway Patrol found that of the 29 identified cases, all but one involved a hand-held phone.

Most occurred while drivers were talking on their phones but some involved reaching for, dialing, getting ready to dial, answering or picking up dropped phones or hanging up.

Based on reported cases, the team estimated that cell phones were involved in at least 0.16 percent of crashes in non-metropolitan areas or about one in 623 reported crashes, she said. The 29 reported cell phone collisions projects to 174 cases annually.

Nine out of 10 crashes, however, occurred within municipal areas.

“In fact, only an estimated 11.8 percent of the crashes identified from the 1996-2000 narrative search were reported by the Highway Patrol,” Stutts said. “Although this number represents only a small percentage of all reported crashes in the state, 1,500 crashes is still too many, especially for something that could easily be avoided. Drivers need to remember that their first responsibility is to pay attention to their driving.”