Cellphones and distracted driving
Why does using a cellphone in the car distract from driving?
What is distracted driving?
It’s a problem known as distracted driving. Along with drunk driving, it remains one of the top causes of traffic accidents and road fatalities (Goodman and Tijerina, 1999).
According to the Center for Disease Control and Prevention, more than a thousand people in the U.S. are injured in car crashes every day due to distracted driving. It also causes thousands of deaths each year, according to the National Highway Traffic Safety Administration. One major cause is clear: multitasking with cellphones—not just texting but also talking while driving (Alm and Nilsson, 1995).
When I first started reading about this problem, it was easy to see why texting—or worse, surfing the web—distracts drivers. It was not as obvious why talking on a phone is distracting. After all, we talk to car passengers all the time. Why does talking on a phone while driving cause car crashes, while talking to passengers doesn’t?
What causes distracted driving?
Using driving simulators (see image above), scientists have been able to study how talking on a phone in the car impairs driving performance. These tests have shown that dialing and driving is as risky as drinking and driving (Redelmeier and Tibshirani, 1997). That’s right, talking on a phone while driving is as dangerous as drinking and driving (Strayer, Drews, and Crouch, 2006).
But why? Many people think it’s because the driver is fidgeting with the phone (known as the “peripheral-interference hypothesis”). Here’s a surprising finding, however. It doesn’t matter whether the driver uses a hand-held phone or a hands-free device. Using a headset is no safer than holding a phone while driving. The accident rates are the same for both (Haque and Washington, 2014).
What interferes with driving performance, therefore, must be cognitive, not manual. In other words, it’s not physical interference from the phone but mental interference from the phone conversation (known as the “attentional-interference hypothesis”).
Simply put, cellphones interfere with driving performance because they divert attention from one task (the driving) to another (the phone conversation). When phone conversations divert attention from driving, drivers are prone to causing car accidents (Redelmeier and Tibshirani, 1997; Strayer and Johnson, 2001).
Why do cellphones distract?
Why do cellphones distract? Cognitively speaking, talking to a car passenger in person and talking to somebody on a phone aren’t the same task.
When talking to a passenger, both driver and passenger have their attention in the same situation. Driving is a task that requires attention to the road, and drivers and passengers share an awareness of this situation. Cognitive scientists call this kind of task-based attention “situation awareness.”
For example, the passenger can serve as an extra set of eyes and ears on the road. When we have a conversation in the car, that passenger is aware of the driver, car, road, and traffic, which can help the driver heed attention. (I bet you can think of at least one time when you called out a light, traffic sign, or pedestrian that the driver didn’t immediately notice.)
The brain has to work much harder to process a conversation when the converser is not physically present. One brain-imaging study discovered that listening on a cellphone led to a 37% decrease in activity in the parietal lobe, which processes spatial tasks (Just et al., 2008).
Again, it makes no difference whether drivers are using hand-held or hand-free devices. Either way, the distraction of talking on a cellphone makes drivers more prone to collisions. Even just hearing a phone ring or buzz can interfere with driving ability (Holland and Rathod, 2013).
Don’t dial and drive!
Think of it this way. Our minds didn’t evolve to divide conscious attention between eyes and ears. When both driver and passenger talk in a car, their eyes, ears, and attention share the same situation. However, if a driver talks to someone else over a cellphone, each converser hears one situation and sees another. The result is divided situation awareness.
By dividing situation awareness, multitasking with cellphones in the car causes thousands of accidents, injuries, and deaths. Again, it’s nearly as bad as drunk driving, so keeping your cellphone off in the car is the best way to not become another distracted driving statistic. (Among the latest stats, distracted driving killed about 3,500 people in 2016, not far behind 10,000 drunk driving deaths.)
Some multitasking activities are okay in certain situations, but when behind the wheel, please don’t dial and drive.
Do these findings surprise you as much as they surprised me? Feel free to leave a comment below, or explore other Educational Topics on this site. Also, for the science geeks out there, I listed the references below.
References
Alm, H., and Nilsson, L. (1995). The effects of a mobile telephone task on driving behavior in a car following situation. Accident Analysis & Prevention, 27, 707-715. doi.org/10.1016/0001-4575(95)00026-V
Center for Disease Control and Prevention. Motor Vehicle Safety: Distracted Driving. www.cdc.gov/motorvehiclesafety/distracted_driving/index.html
Goodman, M. J., Tijerina, L., and Bents, F. D. (1999). Using cellular telephones in vehicles: Safe or unsafe? Transportation Human Factors, 1, 3-42. doi.org/10.1207/sthf0101_2
Holland, C. and Rathod, V. (Jan 2013). Influence of personal mobile phone ringing and usual intention to answer on driver error. Accident Analysis & Prevention, 50, 793-800. doi.org/10.1016/j.aap.2012.07.004
Haque, M.M. and Washington, S. (Jan 2014). A parametric duration model of the reaction times of drivers distracted by mobile phone conversations. Accident Analysis & Prevention, 62, 42-53. doi.org/10.1016/j.aap.2013.09.010
Just, M. A., Keller, T. A., and Cynkar, J. (2008). A decrease in brain activation associated with driving when listening to someone speak. Brain Research, 1205, 70-80. doi.org/10.1016/j.brainres.2007.12.075
National Highway Traffic Safety Administration. Distracted Driving. https://www.nhtsa.gov/risky-driving/distracted-driving
Redelmeier, D. A. and Tibshirani, R. J. (1997). Association between cellular-telephone calls and motor vehicle collisions. New England Journal of Medicine, 336, 453-458. doi.org/10.1056/NEJM199702133360701
Strayer, David L., Drews, Frank A., and Crouch, Dennis J. (2006). A Comparison of the Cell Phone Driver and the Drunk Driver. Human Factors, 48 (2), 381-391. doi.org/10.1518/001872006777724471
Strayer, David L. and Johnston, William A. (2001). Driven to Distraction: Dual-Task Studies of Simulated Driving and Conversing on a Cellular Telephone. Psychological Science, 12 (6), 462-466. doi.org/10.1111/1467-9280.00386