Hands-free calls are just as distracting for drivers, says study
The study, performed by Dr. Shimul Haque of QUT, measured the reaction time of drivers that used the phone hands-free, drivers that actually held their device and ones that didn't use a phone at all during driving. The tests were done in a simulator, presenting the same situation to all drivers.
We took a group of drivers and exposed them to a virtual network which included a pedestrian entering the driver's peripheral vision from a foothpath and walking across a pedestrian crossing. We then monitored the driver's performance and reaction times during hands-free and hand-held phone conversations and without.
It turns out that both the people that used their phones hands-free, and the ones that held it up to their ear, have the same decrease in reaction time – approximately 40% slower than the drivers without a phone. “In real terms this equates to a delayed response distance of about 11 meters for a vehicle travelling at 40 km/h,” said Haque.
Additionally, distracted drivers appear to be more prone to brake excessively, creating a safety concern for the cars that follow them.
According to Dr. Haque, it's the cognitive load required to hold a conversation that's the real distraction, and not whether the driver is holding the phone or not. “In other words the human brain compensates for receiving increased information from a mobile phone by not sending some visual information to the working memory,” explained the scientist. This results in drivers that look at objects, without actually "seeing" them.
source: QUT via SlashGear
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