Voice-to-Text Apps: Study Finds No Safety Benefits

New research findings suggest that voice-to-text applications offer no real safety advantage over manual texting.

Graphic showing various distracted driving data in Texas.  10% of all drivers are using their cell phone right now.  90,378 crashes in 2012 involved driver distraction (including cell-phone use). Nearly 1 in 4 crashes involves driver distraction.  Texting takes a driver's eyes off the road for 4.6 seconds, like driving a football field with eyes closed.

Sponsored by the Southwest Region University Transportation Center and conducted by the Texas A&M Transportation Institute (TTI), the first-of-its-kind study is based on the performance of 43 research participants driving an actual vehicle on a closed course. The TTI analysis is the first to compare voice-to-text and manual texting on a handheld device in an actual driving environment.

Drivers first navigated the course without cell phones and then traveled the course three more times performing a series of texting exercises: once using each of two voice-to-text applications (Siri® for the iPhone and Vlingo® for Android) and once texting manually. Researchers then measured the time it took each driver to complete the tasks. They also noted how long it took for the driver to respond to a light that came on at random intervals during the exercises.

TTI Associate Transportation Researcher Christine Yager, who managed the study, says the findings offer new insight but only a part of the knowledge needed to improve roadway safety. “Understanding the distracted driving issue is an evolving process, and this study is but one step in that process,” she says. Another TTI study now under way examines the motivations and attitudes of distracted drivers. Results from the focus groups and a 3,000-driver survey are expected in late summer and will look at which demographic groups are most affected by distracted driving.

The study elicited widespread interest as evidenced by its media reach around the globe: approximately 8.5 million viewers via broadcast media, 400 million readers (print and online) and 12 million followers via Twitter.

Major findings from the study include:

  • graphic of a grayed out person's voice waves traveling to a smart phone Driver response times were significantly delayed, whichever texting method was used. Drivers took about twice as long to react to sudden roadway hazards, such as a pedestrian in the street, as when they weren’t texting.
  • Drivers spent significantly less time looking ahead at the roadway when they were texting, whichever texting method was used.
  • For most tasks, manual texting required slightly less time than the voice-to-text method, but driver performance was roughly the same with both.
  • Drivers felt less safe when they were texting but felt safer when using a voice-to-text application than when texting manually, even though driving performance suffered equally with both methods.

This Issue

Multiple Modes, One Network

Texas Transportation Researcher: Volume 49, Number 2

Volume 49, Number 2
June 2013
Issue Overview

driver using voice-to-text device while on a busy roadway

“Understanding the distracted driving issue is an evolving process, and this study is but one step in that process.”
Christine Yager, TTI associate transportation researcher

Graphic showing the study's media reach around the globe: 8.5 million viewers via broadcast media, 400 million readers (print and online), 12 million followers via Twitter.

For more information:

Christine Yager
(979) 845-6528

For a video about the study, see http://vimeo.com/64641918.