Everyone knows it's safer to make phone calls or send text messages using your car's hands-free system, right?

Maybe not, according to a new study that suggests the distractions associated with new types of hands-free technology could put drivers at more risk than if they simply picked up their phone and made a call, or even sent a text message the old fashioned way.

"What we found is that relative to paying attention to the road, people who engage in these hands-free activities showed changes in their brain waves, a narrowing of visual attention. They also showed delayed reaction time, and this was especially true of hands-free text messaging tasks that we evaluated," University of Utah researcher Joel Cooper told CTV’s Canada AM.

Cooper and his colleagues carried out the study on behalf of the American Automobile Association. Their findings, released Wednesday, contradict the assumption that, as long as an activity performed while driving is hands-free, it is safe.

Here are some key results of the study, which looked primarily at how drivers reacted to increased mental workload and distractions:

  • As mental workload increased, reaction time slowed;
  • Brain function was compromised;
  • Drivers scanned the road less and tended to focus only on the centre of the road, ignoring things like crosswalks and intersections;
  • Visual cues such as stop signs and pedestrians often went unnoticed.

Cooper and his team measured brainwaves, eye movement and other metrics as participants drove a vehicle while being bombarded with various stimuli.

Listening to the radio ranked as a Category 1 level of distraction, with minimal risk. Talking on a cellphone, either hand-held or hands-free, posed a Category 2, or moderate risk distraction.

However, listening and responding to an in-vehicle, voice-activated email feature increased mental workload and raised distraction levels to Category 3, considered extensive risk.

"Where your eyes are on the road, your hands are on the wheel but your mind is elsewhere, what happens is people's reactions slow and they tend to miss events in the visual environment, they tend to focus on the centre of the road and not scan important locations in the driving environment like a crosswalk or an intersection," Cooper said.

Automakers have been touting the so-called infotainment systems now available in new models, and a five-fold increase in the prevalence of such technologies is expected by 2018 -- surging from 9 million cars and trucks currently on the road in the U.S. with such systems, to 62 million.

AAA spokeswoman Yolanda Cade described it as a "looming" public safety crisis.

"We hope this study will change some widely held misconceptions by motorists," Cade told The Associated Press.

Peter Kissinger, president and CEO of the AAA Foundation for Traffic Safety, the group's safety research arm, said the research answers a lot of questions for the organization.

"People aren't seeing what they need to see to drive. That's the scariest part to me," he told The Associated Press. "Police accident investigative reports are filled with comments like the 'looked, but did not see.' That's what drivers tell them. We used to think they were lying, but now we know that's actually true."

The AAA is calling for:

  • Limits to voice-activated technology, restricting its use to core driving functions such as climate control or windshield wiper operation.
  • The disabling of certain functions, such as voice-to-text technology, while a vehicle is in motion.
  • Educating vehicle owners and mobile device users about the safety risks of infotainment systems.