Drivers texting in actual driving test twice as slow to react — US study

Drivers reading or writing text messages take twice as long to react and are 11 times more likely to miss a flashing light, US researchers have found.

The effect was even greater than many experts had believed, the researchers at the Texas Transport Institute said.

The study is the first published work in the US to examine texting while actually driving a motor vehicle.

The study showed how texting drivers are less able to react to sudden roadway hazards,

Participants went through three major steps.

First, they typed a story of their choice (usually a simple fairy tale) and also read and answered questions related to another story, both on their smart phone in a laboratory setting. Each participant then navigated a test-track course involving both an open section and a section lined by construction barrels. Drivers first drove the course without texting, then repeated both lab tasks separately while driving through the course again. Throughout the test-track exercise, each participant’s reaction time to a periodic flashing light was recorded.

Reaction times with no texting activity were typically between one and two seconds. Reaction times while texting, however, were at least three to four seconds. Worse yet, drivers were more than 11 times more likely to miss the flashing light altogether when they were texting. The researchers say that the study findings extend to other driving distractions that involve reading or writing, such as checking e-mail or Facebook.

The study, sponsored by the Southwest Region University Transportation Center, was managed by Christine Yager, an associate transportation researcher in the TTI Center for Transportation Safety. Forty-two drivers between the ages of 16 and 54 participated in the research.

The researchers also measured each driver’s ability to maintain proper lane position and a constant speed. Major findings further documented the impairment of texting when compared to the controlled driving conditions. Drivers were less able to:

  • safely maintain their position in the driving lane when they were texting and their swerving was worse in the open sections of the course than in barreled sections.
  • maintain a constant speed while texting, tending to slow down in an effort to reduce the demand of the multiple tasks. By slowing down, a driver gains more time to correct for driving errors (such as the tendency to swerve while texting). Speed variance was also greater for texting drivers than for non-texting drivers.

The fact that the study was conducted in an actual driving environment is important, the researchers say. While simulators are useful, the dynamics of an actual vehicle are different, and some driver cues can’t be replicated in a simulator. By using a closed course, researchers can create an environment similar to real-world driving conditions while providing a high degree of safety for the participants.

“Most research on texting and driving has been limited to driving simulators. This study involved participants driving an actual vehicle,” Ms Yager said. “So one of the more important things we know now that we didn’t know before is that response times are even slower than we previously thought.”

The total distance covered by each driver in the study was slightly less than 11 miles, (17.6km). In the interest of safety for both participants and the research staff, researchers minimized the complexity of the driving task, using a straight-line course without hills, traffic or potential conflicts other than the construction zone barrels. Consequently, the driving demands that participants encountered were considerably lower than those they would encounter under real-world conditions.

“It is frightening,” the researchers wrote, “to think of how much more poorly our participants may have performed if the driving conditions were more consistent with routine driving.”

US Federal statistics suggest that distracted driving contributes to as much as 20 per cent of all fatal crashes and that mobile phones constitute the primary source of driver distraction. Researchers point to two numbers to illustrate the magnitude of the texting while driving problem: an estimated five billion text messages are sent each day in the US and at least 20 per cent of all drivers have admitted to texting while driving.

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