Investigations of Cell Phone Use While Driving in NC Jane Stutts William Hunter Herman Huang University of North Carolina Highway Safety Research Center
Project Tasks: • Statewide telephone survey of cell phone users and non-users. • Analysis of characteristics of cell phone-related motor vehicle crashes. • Supplemental data collection by NC State Highway Patrol.
Statewide Telephone Survey Goals • Obtain updated information on cell phone use and user characteristics. • Compare cell phone users to non-users. • Obtain opinions of users and non-users on issues of cell phone safety and regulation. • Obtain baseline measures for future comparisons.
Telephone Survey Conclusions • 3 in 5 drivers have used a cell phone while driving. • Usage highest in 25-39 and 40-54 age groups, and does not differ by gender or race. • Average talk time decreases with age, and is higher for males than females. • 1 in 4 users have a hands-free device, but not all use it.
Survey Conclusions (cont.) • Users perceive talking on phones to be less distracting and less of a safety concern than non-users. • Users less likely to support legislation that would prohibit anything other than hand-held phone use. • Users less likely to support stricter penalties for cell phone drivers in crashes.
Identification and Analysis of Cell Phone Crashes • Computerized search of NC crash report narratives from January 1996 through August 2000 • Search words: answer, carphone, cell, dial • Narratives read to determine their relevance • 452 cell phone crashes identified • 0.04% of all crashes (an underestimate) • Increased from 0.01% in 1996 to 0.15% in 2000
Sample Narratives • Driver 1 bent down to answer car phone and ran into back of Veh. 2 which knocked Veh. 2 into rear of Veh. 3. • Driver 1 stated that he ran off the roadway while trying to reach for his cell phone. • (Not used) Driver 1 stated that she had just got out of the eye doctors office and her pupils were dialated and she ran the red light.
Data Limitations • Search terms may have missed some narratives. • Drivers may not admit they were using a cell phone. • Officers may not ask about cell phone use. • Extent of underreporting is not known. • Hand-held vs. hands-free is not known.
Violations for Crash-involved Cell Phone Users vs. Non-users
Summary of Findings • Cell phone crashes more likely to occur: • On local roads and in urban areas • During mid-day or early afternoon hours • Drivers involved in cell phone related crashes are more likely to be: • Ages 35-55 • Male • Driving sport utility vehicles • Cited for failure to reduce speed or traffic signal violations
Special Data Collection by NC State Highway Patrol • All 8 NC SHP districts participating • Two month data collection period, May 15 - July 14, 2002.
Supplemental Data Collection Form “Complete this form for any crash where a cell phone was in use.” • What type of cell phone was the driver using? (hand-held, hand-held with headset, etc.) • What was the driver doing at the time of the crash? (talking, dialing, answering, etc.) • How important was the cell phone in causing the crash? (very, somewhat, not at all, uncertain) • How did you obtain information about cell phone use in this crash? (observed, driver volunteered, questioned driver, witness report, etc.) • Estimated 11.8% of cell phone crashes statewide reported by NC HP. 1,475 projected crashes annually
Descriptive Results • 29 cell phone crashes statewide over the 2-month data collection period • Only 1 hands-free phone • Predominantly occurred while talking on phone (9 crashes), followed by reaching for phone (5 crashes), dialing (4 crashes) and answering phone (3 crashes) • 86% very significant, 14% somewhat significant in causing crash • Information most often volunteered by driver, but officers also questioned driver.
Cell Phone Crash Projections • 29 cell phone crashes statewide over a 2-month period Translates to 174 crashes annually • But only 11.8% of cell phone crashes statewide reported by NC SHP. 1,475 projected crashes annually
Full report can be accessed at: http://www.hsrc.unc.edu/ Thank You!
Survey Methods • Random digit dial household telephone survey. • Adults ages 18+, NC resident, valid driver’s license. • Targeted 500 users, 150 non-users. • At least 50 respondents in each of following age groups: 18-24, 25-39, 40-54, 55-69, 70+. • Descriptive tabulations and multivariate regression analysis using SAS.
Screener Results • Residency, age, driver license checks, plus “Do you talk on a cell phone while driving?” • 1006 completions, 106 non-completions (90.5% of all contacts) • 550/1006 cell phone users (54.7%)
Percent Using Cell Phone While Driving by Age Adjusted % using cell phone while driving: 58.8%
Cell Phone Use Characteristics- Type of Hands Free System Hands-free 28% Headset 64% Speaker phone 33% Other 3%
Opinions on Cell Phone Legislation(Percent who would vote to support)