January 13, 2014

Distracted Driving Raises Crash Risk

Young woman driving on highway while using smart phone.

Researchers used video technology and in-vehicle sensors to show that distracted driving, particularly among new drivers, substantially raises the risk for car crashes and near crashes. They also found that drivers eat, reach for the phone, text, or otherwise take their eyes off the road about 10% of the time.

About 6% of drivers in the United States are 15 to 20 years old. But these young drivers are involved in about 10% of accident fatalities and 13% of police-reported crashes resulting in injury. Past studies suggest that doing something else while driving—such as eating, talking on the phone, or texting—raises the risk of crashes.

Researchers at NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) and the Virginia Tech Transportation Institute analyzed the driving habits of about 150 drivers for 12-18 months. One group included novice teen drivers in southwestern Virginia who were recruited within 3 weeks of getting their license. Another group of drivers recruited from the Washington, D.C. area had, on average, 20 years of experience and ranged in age from 18 to 72.

The researchers equipped the vehicles with data-acquisition systems developed at Virginia Tech. Four cameras continuously recorded video footage whenever the cars were in motion, while a suite of sensors recorded acceleration, sudden braking or swerving, drifting from a lane, and other data.

When a crash occurred, or drivers had a near miss, the researchers documented whether the drivers were engaged in a distracting activity. They identified episodes when drivers talked, dialed, or reached for a cell phone; reached for another object in the car; adjusted the car’s temperature or radio controls; ate, drank, or looked at a crash or something else outside the car; or adjusted a mirror, seatbelt, or window in the car. The researchers compared the frequency of these activities during a crash or near miss to that during segments of uneventful driving.

In the January 2, 2014, issue of the New England Journal of Medicine, the team reported that the risks of distracted driving were great for newly licensed teen drivers when engaging in a number of tasks. Compared to when they weren’t involved in distracting tasks, novice teen drivers were 8 times more likely to crash or have a near miss when dialing a phone; 7-8 times more likely when reaching for a phone or other object; almost 4 times more likely when texting; and 3 times more likely when eating.

Experienced adults were more than twice as likely to crash or have a near miss when dialing a cell phone. However, they didn’t have an increased risk while engaging in other tasks secondary to driving. The act of talking on a cell phone didn’t itself increase risk among the adult or teenage drivers. However, talking on a cell phone is necessarily preceded by reaching for the phone and answering or dialing.

This study shows that distraction is an important contributor to increased crash risk. “Anything that takes a driver’s eyes off the road can be dangerous,” says study co-author Dr. Bruce Simons-Morton of NICHD. “But our study shows these distracting practices are especially risky for novice drivers, who haven’t developed sound safety judgment behind the wheel.”

Related Links

References: Distracted driving and risk of road crashes among novice and experienced drivers. Klauer SG, Guo F, Simons-Morton BG, Ouimet MC, Lee SE, Dingus TA. N Engl J Med. 2014 Jan 2;370(1):54-9. doi: 10.1056/NEJMsa1204142. PMID: 24382065.

Funding: NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) and the National Highway Traffic Safety Administration.