New Delhi, June 29: Talking on hand-held or hands-free mobile phones at the wheel might be as bad as driving drunk, says a study that compared the performance of drivers who were either talking on cellphones or had consumed vodka.
The study by US psychologists published today in the journal Human Factors has corroborated earlier findings that hands-free mobile phones can be just as distracting to automobile drivers as hand-held.
It has shown that people are as impaired when they drive and talk on mobile phones as when they drive intoxicated at a blood-alcohol limit of 0.08 per cent ' the cut-off that defines illegal driving in the US.
“Driving while talking on a cellphone is as bad or maybe worse than driving drunk, which is completely unacceptable,” said Frank Drews, assistant professor of psychology at the University of Utah.
Drews and his colleagues designed a study in which 25 men and 15 women volunteers were asked to sit on an automobile simulator and drive under four situations ' undistracted, using a hands-free phone, using a hand-held phone, and intoxicated with 0.08 per cent blood-alcohol level achieved by drinking a cocktail of vodka and orange juice.
The study has found that compared with undistracted drivers, drivers who talked on either hand-held or hands-free phones drove slower, were 9 per cent slower to hit the brakes, were 19 per cent slower to resume normal speed after braking and were more likely to crash.
Five years ago, University of Utah researchers had shown that hands-free mobile phones can be as distracting as hand-held phones. In a follow-up study in 2003, they attributed this to “inattention blindness” ' a condition in which drivers stare at road conditions ahead of them, but don’t really see them because they are distracted by the conversation.
The new study also found that drivers with 0.08 blood-alcohol level drove slower than both undistracted drivers and drivers using mobile phones, but drove more aggressively.
However, the study showed that among drunken drivers, neither the accident rates nor reaction times to vehicles braking in front of the driver, nor recovery of lost speed following braking differed significantly from undistracted drivers.
While the lack of accidents among drunken drivers in this study might appear surprising, the researchers say this might be the result of the time of the day during which the study was conducted. The study was done in the morning and the volunteers who got drunk were well-rested. The researchers point out that alcohol-related accidents typically occur in the evenings or night.
They said that drivers who talk to passengers, eat, drink, light cigarettes, apply makeup, or listen to the radio are also likely to get distracted.
Mobile devices that allow drivers to talk, surf the Internet, and send messages may be “substantially more distracting”, the study said.