SALT LAKE CITY — Smartphone technology allows drivers to write emails and texts, or post to sites like Facebook and Twitter, without taking their eyes off the road.
But a new study by the University of Utah suggests that using hands-free devices to talk, text and email increases a driver's mental workload, causing them to scan the road less and potentially miss seeing objects directly in front of them like signs or pedestrians.
"Just because it's hands-free doesn't mean it's risk-free," said University of Utah psychology professor David Strayer, the lead author of the study. "Just because your car might support posting to Facebook while you're driving, it may not be a good idea."
The study, released today and sponsored by the AAA Foundation for Traffic Safety, used a driving simulator on campus and an instrument vehicle in residential Salt Lake City to measure a driver's brainwaves, eye movement and other metrics as they attempted to perform multiple tasks at once.
Thirty-two individuals from the University of Utah, including 22 men and 10 women, participated in the study. They ranged from ages 19 to 36 and all participants reported that they owned a cellphone and used it regularly while driving.
Researchers found that listening to the radio or an audiobook resulted in the lowest level of distraction or minimal risk. Talking on a cellphone, either hand-held or hands-free, resulted in moderate risk.
But listening and responding to an in-vehicle, voice-activated email or text program increased the mental workload of a driver and resulted in a distraction level of extensive risk.
"The mental distraction is pretty substantial," Strayer said.
For the simulator testing, participants were given driving tasks to perform while talking on their cellphone with a friend or using voice-activated programs to send and edit messages.
Sammie Sherwood, a U. senior studying psychology and sociology who participated in the study, said the simulator is a realistic representation of on-the-street driving. She admitted to using her phone in the car "once or twice a day" but said that working on the study made her realize how distracted she can become while driving.
"Especially with the cellphone, I tend to get distracted," she said. "I get a little into the conversation and kind of forget about the driving task."
She said the study has also made her more aware of people using their phones in cars next to hers, which she said is a regular sight on Utah's roads.
"Utah drivers, sometimes, are a little crazy," she said. "On the freeways here, especially in rush hour, you'll see people on phones all the time and they tend to be the ones darting in and out of traffic and cutting people off."
The release of the study follows Monday's presentation by Apple of a new operations system for the company's computers and cellphones. Apple's presentation included an upgraded and expanded version of its Siri software, which allows users to write and send messages and perform other tasks through a series of voice prompts.
Automobile manufacturers have also increasingly worked to integrate on-board computing systems with smartphone technology, offering drivers more opportunity to use their devices without removing their hands from a steering wheel.
AAA officials predict a fivefold increase in these types of "infotainment" systems in new vehicles by the year 2018 and are pointing to the results of the U. study as evidence that regulatory action is needed.
"There is a looming public safety crisis ahead with the future proliferation of these in-vehicle technologies," AAA President and CEO Robert L. Darbelnet said in a prepared statement "It's time to consider limiting new and potentially dangerous mental distractions built into cars, particularly with the common public misperception that hands-free means risk-free."
Strayer said part of the misperception of safety is due to increased availability of infotainment systems in vehicles. He said some vehicle owners and drivers likely assume that because the hands-free technology is offered in a new vehicle, it represents a safe alternative to a hand-held device that has been vetted by the manufacturer.
"The average consumer might be led astray by false assumptions," he said.
In a statement accompanying the release of the study, AAA officials suggested that partners in the automotive and electronics industries look into limiting the use of voice-activated technology to driving-related activities like air conditioning and heating, windshield wipers or cruise control.
They also suggested that certain voice-to-text programs, such as those used in social media applications, email and text messaging, be disabled while a vehicle is in motion.
"This study constitutes the most in-depth analysis to date of mental distractions behind the wheel," Darbelnet said in a prepared statement. "AAA is hopeful that it will serve as a stepping stone toward working in collaboration with auto makers to promote our shared goal of improving safety for all drivers."
In Utah, it is illegal for a driver to text or email while driving.
A new law that went into effect last month bars school-age drivers from all cellphone use while driving, except in cases of emergency or when communicating with parents.
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