Note to the reader: The research on distracted driving among teens is extensive, and in many cases, complicated. Therefore, we have divided the topics of research into several papers. This is Part 1 focusing on distraction and the brain.
A review of the research literature on adolescent distracted driving and the adolescent brain revealed some very important findings. Among them:
- The two main causes for young driver distraction are immaturity and lack of experience of the novice driver. Immaturity limits the cognitive abilities of the driver (e.g., spatial, situational awareness) and increases risk taking among youth, among others. Lack of experience of young drivers requires that they concentrate more on basic driving skills that will become more automatic as the driver becomes experienced.
- There is no such thing as multitasking. We can only do (or think about) one thing at a time. What the brain actually does when we are what we call “multitasking” is switch between one task and another. The brain can switch fairly quickly, leading to the belief that we are actually doing two things at the same time. Any distraction in driving, therefore, takes away from actual driving, even if for a few seconds.
- Use of cellphones and texting while driving create a considerable distraction and therefore risk among young drivers, although texting is more distracting because it requires manipulating the device.
- The use of handheld and hand-free devices ios equally distracting.
- There is some evidence that bans on the use of cellphones and texting and driving may not have much impact on reducing these behaviors among youth.
- Interventions (laws, regulations, policies, training programs, campaigns) can be effective in reducing distracted driving. However, they must be carefully targeted and based on research.
Introduction to the Research
Distracted driving is a major cause of traffic crash fatalities and injuries in the United States, especially among youth. Moreover, with the explosion in the availability and use of cellphone and smartphones, there has been a spike in crashes (and fatalities and injuries) caused by cellphone use, texting and use of social media while driving, again, particularly among young people. According to the National Safety Council, “Cell phone use has grown dramatically over the past 15 years. In 1996, cell phone subscriptions covered only 14 percent of the U.S. population.” http://www.nsc.org/DistractedDrivingDocuments/Cognitive-Distraction-White-Paper.pdf Today, according to the Pew Research Center, “the vast majority of Americans – 95% or 303 million people – now own a cellphone of some kind. The share of Americans that own smartphones is now 77%, up from just 35% in Pew Research Center’s first survey of smartphone ownership conducted in 2011. And, 100% of Americans ages 18-26 have cellphones. 94% have smartphones. 97% of Latino adults own a cellphone. 77% have a smartphone. http://www.pewinternet.org/fact-sheet/mobile/
“Young drivers appear to be most susceptible to distraction related crashes; 16% of all distraction-related fatal crashes in 2008 in the United States (US) are attributed to drivers < 20 years of age, the highest proportion of all drivers. Young drivers are inexperienced compared with older drivers, and this inexperience potentially extends to a reduced ability to judge driving demands in relation to other potentially distracting tasks.”
Journal of Adolescent Health, Volume 54, Issue 5, Supplement, May 2014, Pages S16-S21
The cost of distracted driving crashes has also increased dramatically to over $172 billion per year (as of 2014 according to the National Highway Traffic Safety Administration). This does not include the cost of increases in car insurance rates, especially for teens.
As the problem of distracted driving has increased, particularly using a cellphone o texting while driving, there has been an exponential growth in the body of research on distracted driving in the United States, especially since 2010. National research studies have been conducted under the auspices of the U.S. Department of Transportation (e.g., National Highway Traffic Safety Administration), the Centers for Disease Control and Prevention (CDC), the National Institutes of Health (NIH), the National Safety Council (NSC), by university-base researchers (e.g., Virginia Tech Transportation Institute), as well as research conducted by national organizations, such as the AAA Foundation, and the Insurance Institute for Highway Safety. http://aaafoundation.org/crash-risk-cell-phone-use-driving-case-crossover-analysis-naturalistic-driving-data/ http://www.iihs.org/iihs/topics/t/distracted-driving/topicoverview
It is critically important to understand distracted driving behaviors, especially cellphone use and texting through solid research to develop effective interventions (laws, programs, messages) to reduce the incidence of crashes caused by these behaviors, and hence reduce the cost in lives, injuries and dollars. A question for policymakers, for instance, would be do we know if strict laws banning texting while driving actually reduce this behavior in teens? Or, do we know what types of messages are effective in reaching teens and changing their behavior? Or how parent involvement may help reduce distracted driving among teens. Finally, what programs (skills development, training) to provide young drivers with skills to become safe drivers?
Types of Research on Distracted Driving
The major difficulty in conducting research on distracted driving and the use of cellphones and texting while driving is that it the behavior is not always observable. Second, it is difficult to establish that an accident was actually caused by distracted driving, unless the behavior was observed just before the crash or if the driver admits to the behavior, which is unlikely. Because of this it can be inferred that there is an undercount of reports of crashes due to distracted driving.
The research on distracted driving can be divided into three types of studies that rely on different data collection methods:
- basic research into the impact of distraction on the brain and its potential effect on distracted driving;
- self-reporting of the behavior through surveys of drivers or self-reporting of cellphone/texting by drivers after a crash, which is where most of the statistics are obtained; and
- actual observation of drivers driving, mostly through monitoring drivers over time using devices in the car (e.g., video, electronic sensors), or “naturalistic driving research”
Have organized this summary of the research into: a) research on the effect of distraction on the brain; b) survey results; and results of naturalistic research on distracted driving. This paper will cover the first category.
Effect of Distraction on the Brain
Rather than going individually into the dozens of studies of distracted driving, we will be relying on the work of organizations and researchers that have compiled research results so we can summarize the main findings.
The National Safety Council (NSC) compiled the results of over 30 research studies regarding the effect to distraction on the brain and its impact on driving. It focuses on “inattention blindness caused by the cognitive distraction of a cell phone conversation.” One of the interesting finding is that, contrary to what most people think, and the laws on distracted driving reflect, is that:
The use of hands-free devices does not reduce the risk of distraction or of having an accident compared with the use of a hand-held device.
Some of the other findings:
- Contrary to what many teens believe, “multitasking is a myth. Human brains do not perform two tasks at the same time. Instead, the brain handles tasks sequentially, switching between one task and another. Brains can juggle tasks very rapidly, which leads us to erroneously believe we are doing two tasks at the same time.” (emphasis ours)
“Multitasking is a myth. Human brains do not perform two tasks at the same time”
- “The brain not only juggles tasks, it also juggles focus and attention. When people attempt to perform two cognitively complex tasks such as driving and talking on a phone, the brain shifts its focus (people develop “inattention blindness”). Important information falls out of view and is not processed by the brain.
- “Research studying the impact of talking on cell phones while driving has identified slowed reaction time to potential hazards are tangible, measurable and risky. Longer reaction time is an outcome of the brain switching focus. This impacts driving performance.” “Research studying the impact of talking on cell phones while driving has identified slowed reaction time to potential hazards are tangible, measurable and risky. For example, if a vehicle is traveling 40 mph, it goes 120 feet before stopping. This equals eight car lengths (an average car length is 15 feet). A fraction of-a-second delay would make the car travel several additional car lengths.
- “Even small amounts of time spent switching can lead to significant risks from delayed reaction and braking time. For example, if a vehicle is traveling 40 mph, it goes 120 feet before stopping. This equals eight car lengths (an average car length is 15 feet). A fraction of-a-second delay would make the car travel several additional car lengths.”
- “A Carnegie Mellon University study produced fMRI pictures of the brain while study participants drove on a simulator and listened to spoken sentences they were asked to judge as true or false. “…listening to sentences on cell phones decreased activity by 37 percent in the brain’s parietal lobe, an area associated with driving. In other words, listening and language comprehension drew cognitive resources away from driving.”
- “Inattention Blindness – … drivers using hands-free and handheld cell phones have a tendency to “look at” but not “see” objects. Estimates indicate drivers using cell phones look at but fail to see up to 50 percent of the information in their driving environment.”
- “Drivers talking on hands-free cell phones are more likely to not see both high and low relevant objects, showing a lack of ability to allocate attention to the most important information.
- “Hands-free phone use led to an increase in reaction time to braking vehicles in front of drivers, and reaction time increased more and crashes were more likely as the traffic density increased.” Even using a hands-free device increases risk.
Note to policymakers and advocates
“Nearly all legislation focuses on banning only handheld phones or only texting while driving. All state laws and many employer policies allow hands-free cell phone use.”
Shouldn’t we advocate for banning hands-free devices, especially for novice or young drivers?
In a research review article Young Driver Distraction: State of the Evidence and Directions for Behavior Change Programs (Lisa Buckley, Ph.D. a,b,*, Rebekah L. Chapman, Ph.D. b , and Mary Sheehan, Ph.D., Journal of Adolescent Health, December 2013) the authors compiled research that provides other evidence of the impact of distraction and
adolesdcentadolescent driving[RB1] .
- “Adolescent drivers are overrepresented in distraction-related motor vehicle crashes. A number of potential reasons for such an elevated risk include driving inexperience, high adoption of communication technology, increased peer involvement, and tendency to take risks, which render young drivers particularly vulnerable.
- “In a study comparing the behavior of young drivers with experienced drivers in an instrumented vehicle, 29% of participating young drivers interacted with a music device or cell phone and glanced away from the road for more than 3 second, whereas none of the experienced drivers glanced away for such a period.
There are many factors that affect driving behavior, including culture, the environment, distracted driving laws (e.g., bans on cell phone use or texting), individual beliefs, personality and passenger interaction. However, the two the main factors for youth distracted driving are driver maturity and driver skills (driver inexperience). More immature drivers tend to higher risk takers. That would suggest that laws raising the age for driver licensure would contribute to reducing teen crashes. However, skills are critically important as well and therefore programs to enhance driving skills among youth could also have an impact on distracted driving.
- “… inexperience means (adolescent drivers) necessarily allocate greater attention to aspects of driving that may later become automatic, which leaves fewer attentional resources available for secondary task. In addition, it has been suggested that adolescent inexperience is associated with lower comprehension of driving safety, risk, and consequence, and less fully developed processing capabilities aligning with the stage of development.”
In another literature review Adolescence, Attention Allocation, and Driving Safety Daniel Romer, Ph.D. a,*, Yi-Ching Lee, Ph.D. b , Catherine C. McDonald, Ph.D., R.N. b,c , and Flaura K. Winston, M.D., Ph.D. b Journal of Adolescent Health, the authors provides a comprehensive review of the research on adolescent driving, focusing on: “…major explanations for these attention failures with particular focus on the roles that brain immaturity and lack of driving experience play in causing attention problems. The review suggests that the potential for overcoming inexperience and immaturity with training to improve attention to both the driving task and hazards is substantial. Nevertheless, there are large individual differences in both attentional abilities and risky driving tendencies that pose challenges to novice driver policies. Research that can provide evidence-based direction for such policies is urgently needed.”
Among the findings (emphasis ours):
- “For adolescent drivers, the risk is incomplete maturation of cognitive and motor skills, including working memory, visual-spatial attention, and speed of processing.”
- “However, adolescents are also novice drivers, and so it is important to separate the effects of inexperience from developmental factors, in particular whether adolescents lack the ability to attend to driving tasks and road hazards due to immaturity in brain development or are more susceptible to errors of misallocated attention due to inexperience.”
- “…a study of the effects of cell phone use in a simulated driving environment  found that cell phone use was equally distracting to novice adolescent drivers ages 14-16 years as to more experienced adult drivers ages 21-52. Measures of situational awareness revealed that both groups suffered deficits in awareness of driving conditions that could affect hazard detection.”
- The researchers attributed the effects of cell phone use to increased cognitive load that interfered with the ability to maintain situational awareness. However, the brain imaging research cited earlier suggests that even removing the need to hold or dial the phone (e.g., using voice-activated technology), will not eliminate all aspects of distraction created by talking on phones.”
- Young adult drivers (ages 18- to 21 years) also exhibited adverse effects of texting while driving in a simulated environment. The drivers spent less time looking at the road and missed signs directing them to change lanes.
- “… the research reviewed suggests that significant opportunities exist to train the skills needed to become a safe driver.” In other words, skills development m may compensate for the lack of maturity or inexperience. (and inattention/distraction)