Speech-to-text systems: Extensive risk
Speech-to-text systems allow drivers to send texts and emails by speaking, then having the technology translate words into a written message. Some systems also allow drivers to complete other tasks, such as updating their Facebook page.
These systems were deemed significantly distracting -- and risky.
"Increased mental workload and cognitive distractions can lead to a type of tunnel vision or inattention blindness where motorists don't see potential hazards right in front of them," explains Peter Kissinger, the president and CEO of the AAA Foundation for Traffic Safety, in a statement.
Hamilton notes that AAA tested a speech-recognition system in which fidelity was perfect. Most commercially available systems do not meet this standard, he says, resulting in a need to review or correct garbled translations. That could mean an even higher level of distraction.
"Our estimate is somewhat conservative," he says.
With the car insurance industry warning that driver distractions can be deadly, researchers are hoping for more dialogue about the safe use of hands-free devices.
"We're not trying to say that these technologies can't be in vehicles," Hamilton says. "We're just trying to put the brakes on their wholesale proliferation."