Driven to Distraction
Driving and cell phones don’t mix.
Adapted from: American Psychological Association, February 1, 2006
1. Cell phones may be convenient but there's one
place they seem to do more harm than good – and
that's behind the steering wheel. Psychological
research is showing that when drivers use cell
phones, whether hand-held or hands-off, their
attention to the road drops and driving skills become
even worse than if they had too much to drink.
Research has found that cell-phone use is
associated with a four-fold increase in the odds of
getting into an accident – a risk comparable to that of driving with blood alcohol at the legal limit.
2. But cell phones aren't the only cause for concern. A number of newly emerging, even more
exciting and time-consuming in-car technologies, such as navigational displays and Internet
browsers, although developed to make long rides more productive, also present new challenges
for drivers. Cognitive psychologists and engineers are teaming up to document how these new
gadgets affect driving performance and traffic safety.
The Research Studies
3. David Strayer, PhD, of the Applied Cognition Laboratory at the University of Utah, has studied
cell-phone impact for more than five years. His lab, using driving simulators, has obtained
scientific evidence that cell-phone conversations disrupt driving performance. Human attention
has a limited capacity, and studies suggest that talking on the phone causes a kind of
“inattention blindness” to the driving scene.
4. In one study, when drivers talked on a cell phone, their reactions to events (such as braking
for a traffic light or a slowing vehicle) were significantly slower than when they were not talking
on the cell phone. Sometimes, drivers were so impaired that they were involved in a traffic
accident. Listening to the radio or books on tape did not impair driving performance, suggesting
that listening alone is not enough to interfere. However, being involved in a conversation takes
attention away from the ability to process information about the driving environment well enough
to safely operate a motor vehicle.
5. According to Strayer's laboratory research, cell-phone drivers were also more likely to miss
traffic signals and often failed to see billboards and other signs. A special eye-tracking device
measured where, exactly, drivers looked while driving. Even when drivers directed their gaze at
objects on the road (during simulations), they still didn't “see” them because their attention –
during a cell-phone call – was elsewhere.
6. Further evidence came from a 2003 Spanish study that found, in a rare experiment using
drivers in real cars on actual highways, that complex phone conversations affected visual
scanning and reduced a driver's ability to detect, discriminate among and respond to visual
targets – by as much as 30 percent. In this study, by psychologists Miguel Angel Recarte
Goldarecena, PhD, of the Universidad Complutense in Madrid, and Luis Miguel Nunes
González, PhD, of Spain's Administration for Traffic Safety, found equivalent effects from
hands-free phone and live in-car conversations. In a 2002 study, they had found that simple
conversations could be held with no interference. They concluded that the complexity of the
conversation was what compromised concentration, whether the driver talked by phone or to a
passenger. Thus, distractions inside one's own head can be just as disruptive as environmental
distractions.
7. Strayer and his colleagues compared data for hand-held and hands-free devices and found
no difference in the impairment to driving. This, they say, raises doubts about the scientific basis
for laws that prohibit only hand-held cell phones.
8. The Utah lab is also measuring the increased risk associated with cell-phone use relative to
other real-world activities – most recently, alcohol consumption. Disturbingly, forthcoming
research will show that talking on a cell phone (even hands-free) hurts driving even more than
driving with blood alcohol at the legal limit. When talking on a cell phone, drivers using a
simulator were slower to brake and had more “accidents” than when they weren't on the phone.
Their impairment level was actually a little higher than that of people intoxicated by alcohol.
Why Does This Happen?
9. Strayer's lab is building a theoretical account for why cell phone use disrupts driving
performance. So far, the evidence points to conversations forcing drivers to withdraw their
attention from the visual scene.
10. Frank Durso, PhD, with Kerstan Mork and John Morris of Texas Tech University, are also
attempting to define the nature of the distraction. Is it a specific cognitive function? Is it attention,
a broader enabler of cognitive function? More concretely, is it a conflict between the mental
image and the current situation, such as an “out-of-the-car” conversation that puts drivers
somewhere else mentally? The answer could help policy makers determine how to suitably
regulate these devices. With or without legislation, says Durso, it's important to raise drivers'
consciousness about the dangers of distraction.
From Research to Real Life
11. First and most obviously, drivers can make themselves, their passengers and other people
on the road safer by putting down their cell phones. The standard advice is to park in a safe
place to make or take calls; at the very least, pull over to the curb or a highway shoulder if
phone communication is truly urgent.
12. Second, drivers should also be aware that whether a cell phone is hands-on or hands-free
makes no difference in terms of mental distraction. According to the research, the mental
activity of conversation, whether in person or over the phone, is what takes one's mind off the
road. What happens in the head happens regardless of what happens with the hands.
13. Third, drivers tempted to talk on the mobile might ask themselves if they would drive drunk.
If not, they should put down the phone.
14. Fourth, drivers can pay attention to the nature of distraction in the car – with heightened
awareness that new devices aimed at a better driving “experience” can have unintended side
effects. Multitasking in or out of the car has been shown in many psychological experiments to
divide attention and limit working memory – both essential to safe driving. Especially in the car,
drivers should aim for the thoughtful use of any new devices or gadgets.
15. Finally, drivers need to remember that warnings (and, in some places, legislation) about cellphones and driving arise from studies of drivers of varied ages, educational levels, and years of
driving. Sensitivity to distraction while driving has nothing to do with smarts or skill. In fact,
psychologist Durso and his doctoral student Andy Dattel point out that although experts can do
many things automatically, detecting hazards is not among them. Thus, Durso says, “anything
that disrupts resource management can have consequences even in experts.”
Sources & Further Reading
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Perception, 27, 951-964.
Crundall, D. & Underwood, G. (1998). The effects of experience and processing demands on visual
information acquisition in drivers. Ergonomics, 41, 448-458.
Duncan, J., Williams, P., & Brown, I. (1991). Components of driving skill: Experience does not mean
expertise. Ergonomics, 34, 919-937.
Durso, F. T., & Dattel, A. R. (in press). Expertise in transportation. In K. A. Ericcson, N. Charness, P. J.
Feltovich, & R. R. Hoffman (Eds.), The Cambridge Handbook of Expertise and Expert Performance,
Cambridge University Press.
Groeger, J. A. (2000). Understanding driving: Applying cognitive psychology to a complex everyday
task. Hove, UK: Psychology Press.
McCarley, J.S., Vais, M.J., Pringle, H., Kamer, A.F., Irwin, D.E., & Strayer, D.L. (2004). Conversation
disrupts change detection in complex traffic scenes. Human Factors, 46, 424-436.
Nunes, L. M. and Recarte, M.A. (2002). Cognitive demands of hands-free- phone conversation while
driving. Transportation Research, Part F, Special Issue: Eye Movements, Attention and Driving
Behaviour, 133 -144.
Recarte Goldarecena, M. A. & Nunes González, L. M. (2003). Mental workload while driving: Effects on
visual search, discrimination and decision making. Journal of Experimental Psychology: Applied,
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Sohn, Y. W., & Doane, S. M. (2003). Roles of working memory capacity and long-term working memory
skill in complex task performance. Memory & Cognition, 31, 458-466.
Strayer, D. L., & Johnston, W. A. (2001). Driven to distraction: Dual-task studies of simulated driving and
conversing on a cellular phone. Psychological Science, 12, 462-466.
Strayer, D. L., Drews, F. A. & Johnston, W. A. (2002). W hy do cell phone conversations interfere with
driving? Proceedings of the 81st Annual Meeting of the Transportation Research Board,
Washington, DC.
Strayer, D. L., Drews, F. A. & Johnston, W. A. (2003). Cell phone induced failures of visual attention
during simulated driving. Journal of Experimental Psychology: Applied, 9, 23-23.
Strayer, D. L., Drews, F. A., & Johnston, W. A. (2003). Are we being driven to distraction? Public Policy
Perspectives, Vol. 16, 1-2. (Published by the Center for Public Policy and Administration, University
of Utah).
Strayer, D. L., Drews, F. A. & Crouch, D. J. (2003). Fatal distraction? A comparison of the cell-phone
driver and the drunk driver . In D. V. McGehee, J. D. Lee, & M. Rizzo (Eds.) Driving Assessment
2003: International Symposium on Human Factors in Driver Assessment, Training, and Vehicle
Design. Published by the Public Policy Center, University of Iowa (pp. 25-30).