Best's Review



The Last Word
On the Road Again

Modifying roadway design can drive down the frequency and severity of distracted driving accidents.
  • Lori Chordas
  • February 2019
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Every day in the United States nine people are killed and another 1,000 are injured as a result of crashes involving a distracted driver, according to the Centers for Disease Control and Prevention.

While the use of cellphones and smart devices, eating and drinking, reading and reaching for objects while driving are the cause of many of those crashes, roadway design can also contribute to those numbers.

Roadway environments have a direct correlation with both the frequency and severity of distracted driving vehicle collisions, according to a recent study by The Ohio State University Fisher College of Business's Risk Institute. The Risk Institute is a consortium of forward-thinking companies and academics focused on an integrated, interdisciplinary approach to risk management.

Urbanized areas and interstate highways have the highest risk for distracted driving-related accidents, according to the study, which is based on 1.4 million police records obtained from the Ohio Department of Transportation for crashes that occurred between 2013 and 2017.

“Severity significantly increases when people using cellphones are driving on highways at speeds of 70 mph compared to driving 35 mph on local roads,” said Zhenhua Chen, who along with Youngbin Lym wrote the study. Chen is an assistant professor in city and regional planning at Ohio State's Knowlton School of Architecture and a research fellow at the Risk Institute. Lym is a PhD student in city and regional planning.

Work zones also increase the frequency and severity of distracted driving accidents. In fact, crashes in those areas are two times more likely to be fatal, according to the study, which was funded by the Property Casualty Insurers Association of America, now merged with the American Insurance Association and known as APCI.

Roundabouts, or circular intersections where drivers travel counterclockwise around a center island, have the most significant effect on reducing the severity of those crashes, Chen said. “That's because roundabouts have more curvatures and attract the attention of drivers who are forced to slow down and put down their phones when driving around them,” he said.

Roadways with a median or a shoulder with an asphalt pavement also drive down the frequency of accidents caused by preoccupied drivers.

Distracted driving has long been a concern of insurers, transportation planners, policymakers and others. The advent of the smartphone heightened that concern. In 2017, cellphone usage caused nearly 1.5 million auto accidents in the United States, according to the National Safety Council.

Younger drivers—particularly those between 20 and 24 years of age—account for the highest percentage of crashes from distracted driving and other causes, according to the study.

Chen said he hopes findings like those will help transportation planners and legislators better understand how the frequency and severity of distracted driving crashes vary by road environment and spur the creation of solutions and legislation to help curb the issue.

The insurance industry is also trying to drive down the number of distracted driving accidents. “The good news is that crash frequency has leveled off in recent months,” said Robert Passmore, assistant vice president at APCI. Additionally, some states have passed distracted driving laws or are trying to bring their texting or handheld laws up to date to reflect the use of newer electronic devices. “Our focus now and going forward is to work with safety groups and others affected by distracted driving to try to get even more laws passed that ban hand-held cellphone use and further discourage texting while driving,” he said.


Lori Chordas is a senior associate editor. She can be reached at

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