The study tracked the eye glances of drivers and labeled as most dangerous those tasks that drew drivers' eyes away from the road the longest.
By that measure, sending text messages while driving was the most dangerous of all the tasks. It increased the risk of a crash over 23 times for truck drivers and is equivalent to "traveling the length of a football field at 55 mph without looking at the roadway," the study said.
Dialing cell phones while driving is also dangerous, although less so. It increased the crash risk nearly 6 times for truck drivers and nearly 3 times for drivers of cars.
"there is an alarming amount of misinformation and confusion regarding cell phone and texting use while behind the wheel of a vehicle," said institute director Dr. Tom Dingus, who added that one purpose of the study was to clear up misconceptions created by other studies that relied on simulated driving rather than actual driving.
For example, talking and listening on cell phones is not nearly as dangerous as driving drunk, the study said, because drivers talking on cell phones can still watch the road.
Also, cell phone headsets offer little additional protection from crashes unless they're used with voice-activated phones.
The institute said that text messaging should be banned for all drivers and that cell phones should be banned for newly licensed teen drivers, because they're four times more likely than adults to get into a crash.
Several states, including California, have already banned texting while driving, and Sen. Charles Schumer, D-NY, has said he will introduce a bill to ban the practice nationally.
Last year, the engineer of a Metrolink commuter train in Los Angeles was found to be sending text messages moments before his train crashed into a Union Pacific locomotive, killing himself and over 20 others and injuring 135.
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