If a motorist is driving erratically, chances are nearby motorists will phone the police or highway patrol and alert them to a drunk driver. A new study shows these callers may be as dangerous on the road as the intoxicated driver.
The study was published in the summer 2006 issue of Human Factors: The Journal of the Human Factors and Ergonomics Society, and was picked up by newspapers around the world via the Reuters news agency.
Forty volunteers drove a simulated 24-mile course four different times: while undistracted, while using a handheld cell phone, while using a hand-free cell phone, and while intoxicated.
The participants were given a vodka-orange juice mixture to induce a blood-alcohol content of 0.8, the average level of impairment across the United States. Verified with a breath monitor, the level was likened to a 170-pound man quaffing four drinks on an empty stomach in one hour.
When intoxicated, the volunteers followed other cars more closely and braked 23 percent more forcefully, a potential problem for motorists behind them. They also had twice as many close calls as they did when sober, defined as stopping less than 4 seconds away from a collision.
In one respect, the test showed cell-phone users were even more dangerous than intoxicated drivers. Three study participants rear-ended the simulated car in front of them. All were talking on cellphones and none was drunk, the researchers said.
They said they were surprised that the drunk drivers were accident-free, and urged people not to misconstrue the results as suggesting drunk driving is safe.
Researchers found no difference between drivers who used hand-held phones and those who used the hands-free variety, a result that didn’t surprise Roberto Rodriguez, director of the New Jersey Division of Highway Traffic Safety. “You are not cognizant of what is going on around you” when having a phone conversation, he explained in an interview with the Philadelphia Inquirer. “That is the danger.”
Frank Drews, an assistant professor of psychology at the University of Utah, worked on the study. “If legislators really want to address driver distraction, then they should consider outlawing cell phones while driving,” he told Reuters. “Driving while talking on a cell phone is as bad as or maybe worse than driving drunk.” Alcohol is involved in 40 percent of the 42,000 annual traffic fatalities in the United States, he added.
At any given moment during the day, 10 percent of drivers on United States roads are making or taking business or social calls, according to a 2005 estimate by the National Highway Traffic Safety Administration published in the Philadelphia Enquirer article. The article noted that Connecticut, New Jersey and New York are the only states where calling from the car is banned. The ban covers only hand-held phones, a concession to the wireless phone industry.
The study may increase the number of states that ban driving while talking on a hand-held phone, and expand the ban to include all types of car phones.
Sources: Reuters; Philadelphia Inquirer