Texting while driving may pose a unique risk compared to other forms of distracted driving, according to an experiment recently published in the journal Scientific Reports.
Unlike driving while absent-minded or driving while emotional, driving while texting actually caused study participants to drive unsafely by deviating from the lines. Comparatively -- and counterintuitively -- the cognitive and emotional distractions actually made participants drive even more safely and in an even straighter line.
The researchers attributed this hyper-focus despite distracting thoughts to a “sixth sense” that corrects driving deviations.
"The driver's mind can wander and his or her feelings may boil, but a sixth sense keeps a person safe at least in terms of veering off course,” said lead author Ioannis Pavlidis, a computer science professor at the University of Houston’s Computational Physiology Lab. "What makes texting so dangerous is that it wreaks havoc onto this sixth sense."
The study’s findings underscore the dangers of texting while driving, which has in the past been compared to drunk and drugged driving because of how dangerous it can be. Pavlidis hopes that the research will help develop a car monitoring system that can sense when a person is distracted by a screen while driving.
What we knew before:
Texting while driving is a far more dangerous distraction compared to eating, talking, adjusting music or using in-vehicle navigation systems, because it takes a person’s eyes off the road for longer and more frequently. The U.S. government calls texting while driving “by far the most alarming distraction," and some research argues that drivers who text are just as impaired as people who drive while drunk.
Distracted driving is also a serious public health problem. In 2013, 3,154 people died in crashes linked to distracted driving, and injuries linked to distracted driving are up. Some 424,000 people were injured in 2013, an almost 10 percent increase since 2011.
Because of statistics like these, 46 states and Washington, D.C. have laws that ban all drivers from text messaging. Among the four states without an overall ban, two ban texting for new drivers and one bans texting for school bus drivers.
The study details:
Pavlidis wanted to study the effects of three different types of distractions -- cognitive, emotional and physical -- on drivers.
He recruited 59 participants to use a high-fidelity driving simulator under two different conditions: normal and stressed. Under normal conditions, participants drove on a straight highway to establish baseline measures of steering and driving performance, as well as their bodily response to the driving exercise.
Then, to stress the drivers, Pavlidis distracted them in different ways. Some participants got cognitive distractions in the form of questions meant to induce a state of absent-mindedness, including simple math questions. Some were emotionally distracted with highly charged questions like, "Have you ever lied on a resume?"
Lastly, some were asked to operate the driving simulator while texting a message with one hand.
Pavlidis found that, compared to the baseline drives, participants’ physical stress reactions were heightened in response to all three different distractions. Their hands were also more “jittery” on the wheel, making more movements than during undistracted drives. But in terms of driving performance, participants drove much more safely than baseline when they were distracted with math questions or emotionally charged thoughts. People who were asked to text while driving, on the other hand, actually crossed over into other lanes.
What may actually happen in your brain when you text and drive:
Pavlidis theorizes that when a driver is distracted, the anterior cingulate cortex of the brain takes over to correct errors due to stress. But the ACC’s interventions didn’t work during the texting stressor, and Pavlidis thinks that this is because the ACC needs input from the eyes and the hands to know how to drive safely and correct any mistakes. If this hand-eye coordination breaks because a driver diverts their eyes to the phone and uses a hand to text instead of steering, the ACC can’t function properly as a driver’s “sixth sense.”
"The worst thing is to be physically distracted,” Pavlidis said. "That will lead outright to lane deviation and a possible accident."
The research was partly funded by the Toyota Class Action Settlement Safety Research and Education Program, which is a research foundation established after a class action lawsuit against the car company. Toyota did not have any input in the study.
How this could affect you:
If you’re still texting while driving, stop. This study and others show that texting is uniquely distracting because it breaks the eye-hand coordination loop required to steer safely. The best thing to do while driving is to keep your smartphone in your purse or glove compartment while on the road, to avoid distractions and the temptation to use it at red lights, said Pavlidis.
People who use their smartphone for navigation should invest in a device to mount the phone to the dashboard of the car, putting the screen at eye level and keeping it out of hands and laps.
If you must answer or make calls while driving, invest in a bluetooth microphone system and use your smartphone’s voice activation commands to do so safely. A 2013 report published by the National Highway Traffic Safety Administration found that using a handheld cellphone is linked to an increased risk of crashes and near-crashes, while portable and integrated hands-free device use is not.
“As far as you keep your hands and eyes where they should be, you’re probably safe,” said Pavlidis of such half-measures like hands-free devices and voice activated commands. "But every time you do otherwise, it’s like a pressure cooker that may blow off its lid."