Telematics system developers ATX and OnStar are both touting
studies conducted by the Virginia Tech Transportation Institute.
The studies indicate that for reducing driver distraction, voice
is preferable to manual data entry for texting in a vehicle, and
voice is also preferable to manual methods for entering
navigation destinations. According to the studies, the number of
eye glances to the mobile phone for manual texting was 20 times
the number of glances to the button that initiates voice
texting. The percentage of time a driver’s eyes were off the
road was shorter when using the voice interface than with
comparable tasks using a handheld phone. All handheld tasks
required significantly more mental workload demand – more than
double on average – than voice-based tasks. Also, according to
the study, voice-based systems essentially erased the gap that
exists between younger and older drivers in driving performance
when using handheld devices. Some say the method a driver uses
for texting in a moving vehicle