Vehicular accidents remain as one of the leading causes of accidental deaths in the United States, according to a new report by the National Safety Council (NSC). Many of these incidents can be blamed on drivers using their cellphone while behind the steering wheel.
Cellphone-related vehicular accidents have prompted authorities to urge drivers not to use their mobile phones while driving but it appears that the threat holds true even for drivers using hands-free devices.
Researchers of a new study found that talking on a hands-free phone while driving a car is just as hazardous as holding the device in the hands.
For the study, published in the Transportation Research journal, study researcher Graham Hole, from the University of Sussex, and colleagues asked participants to perform video-based hazard-detection tasks.
The researchers found that distracted participants, who listened to sentences and decided if these were true of false, were slower than undistracted participants when it comes to responding to hazards. Distracted participants also detected fewer hazards or were unable to see hazards despite being able to focus their eyes on them.
The researchers likewise observed that the impairments were worse for those distracted by imagery-inducing statements suggesting that for those who drive while talking, the most dangerous kind of conversations are those that spark visual imagination.
The findings suggest that phone conversation entails more use of the visual processing resources of the brain than earlier believed.
"Telephone conversations may interfere with driving performance because the two tasks compete for similar processing resources, due to the imagery-evoking aspects of phone use," the researchers wrote in their study.
The researchers said that anything that causes drivers to imagine something, which include passengers, may affect their driving performance. Nonetheless, passengers pose lesser risk compared with mobile phone conversations.
"Chatty passengers tend to pose less of a risk than mobile phone conversations. They will usually moderate the conversation when road hazards arise," said Hole.
"Someone on the other end of a phone is oblivious to the other demands on the driver and so keeps talking."
The findings of the study support results of earlier studies on the dangers of using hands-free device in cars.
A study conducted by AAA Foundation for Traffic Safety and the University of Utah found that in-dash systems up mental distraction which increases risk of accidents and that hands-free use of the iPhone's Siri causes high level of mental distraction among drivers.
