Newly compiled results from more than six million miles of observed driving suggest that it's the act of taking one's eyes off the road, more than the cognitive distraction of talking or listening on the phone, that's most dangerous.
The Virginia Tech Transportation Institute study included data—all gathered 'naturalistically,' meaning via camera systems and instruments in real-world driving—for dialing a cellphone, talking/listening to a cellphone, and reaching for an object. That data was also gathered for both light-vehicle drivers and truck drivers, where text messaging was included.
According to the findings, dialing was 2.8 times as risky as non-distracted driving, while talking/listening and reaching for an object were 1.3 and 1.4 times as risky, respectively. Truck drivers were at much higher risk when dialing a cellphone, with 5.9 times the risk of crash or near-crash event compared to non-distracted driving; reaching for an object was also far riskier for the truck drivers, at 6.7 times that of non-distracted driving, while the risk of talking/listening was unchanged versus driving with no distraction.
The real shocker was text messaging; for the truck drivers, texting brought 23.2 times the risk of a crash or near-crash event. The research showed that text messaging brought the driver's eyes away from the road for the longest time of all the tasks; for the trucker, it was the equivalent of covering the length of a football field at 55 mph without looking at the road, the researchers said.
"Recent results from other researchers using driving simulators suggest that talking and listening is as dangerous as visually distracting cell phone tasks," state the researchers in a release from the Institute. "The results from VTTI's naturalistic driving studies clearly indicate that this is not the case."
The researchers say that while cognitively intense tasks such as emotional conversations or books on tape can have a more measurable effect in the lab, they might not have the same effect in real driving tasks.
"Using simple fatal crash and phone use statistics, if talking on cell phones was a risky as driving while drunk, the number of fatal crashes would have increased roughly 50 percent in the last decade instead of remaining largely unchanged," the researchers argue.
Among the recommendations from the VTTI researchers are that texting should be banned for all drivers; that users migrate to voice-activated hands-free systems to that they don't have to take their eyes off the road; and that all cellphone use should be banned for teen drivers.
The New York Times also cites a new University of Utah study, based on laboratory research rather than real-world observation, that suggests the risk when texting to be eight times higher than when not. According to the Times, only 14 states currently ban texting while driving.