AAA Foundation for Traffic Safety conducted a study that tested the different levels of distracted driving while listening to the radio, talking on a handheld phone, text messaging and voice-to-text messaging.   The perils in hands-free messaging exceeded the levels of distracted driving while holding a conversation on a handheld phone. 

Voice-to-text messaging behind the wheel caused a “large” amount of distraction compared to “moderate/ significant” for holding a phone conversation.  Listening to music or an audio book was deemed a “small” mental distraction. 

The study used drivers mostly in their 20s and 30s, all of the participants had good driving records and they performed driving tasks first in the lad and then in a driving simulator and lastly in a residential area.  The researchers measured the driver’s reaction time and their brainwave activity with caps’ secured to the driver’s heads to see what was most distracting.

A Transportation Department-funded study that deemed hands-free texting distracted drivers as much as messaging with a handheld device. 

Automakers promote the voice-based messaging as a safer alternative to taking hands off the wheel to place a call and talk on a handheld phone.  The study found that both methods slowed driver reaction times almost two times than when they were not texting.  The study also found that it took drivers longer to complete a text when speaking than when manually typing.  Jacob Nelson, AAA's director of traffic safety advocacy and research, said "the guielines don't address the distraction of taking one's mind off driving."  The safest driver is an attentive driver.  Keep your hands, eyes and mind on the road to prevent accidents.