When texting drivers use the voice-to-text method instead of texting manually, they are still endangering themselves and others on the road, new research findings suggest.

The new study, conducted by the Texas A&M Transportation Institute (TTI), was based on the performance of 43 research participants driving an actual vehicle on a closed course. Other research efforts have evaluated manual versus voice-activated tasks using devices installed in a vehicle. The TTI analysis, however, is the first to compare voice-to-text and manual texting on a handheld device in an actual driving environment.

The Southwest Region University Transportation Center (SWUTC) sponsored the study. SWUTC is a part of the University Transportation Centers Program, which is overseen by the U.S. Department of Transportation’s Research and Innovative Technology Administration.

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

According to TTI, driver response times were significantly slowed, regardless of the texting method used. In each case, drivers took about twice as long to react as they did when they weren’t texting. With slower reaction times, drivers are less able to take action in response to sudden roadway hazards, such as a swerving vehicle or a pedestrian in the street.

The amount of time that drivers spent looking at the roadway ahead was significantly less when they were texting, no matter which texting method they used, TTI said. And for most tasks, manual texting required slightly less time than the voice-to-text method, but driver performance was roughly the same with both. 

The study also revealed that voice-to-text applications gave drivers a bit of a false sense of security. Though drivers felt less safe when they were texting by any means, they indicated they felt safer when using a voice-to-text application than when texting manually. However, their driving performance suffered equally with both methods.

Christine Yager, a TTI associate transportation researcher who managed the study, said the findings offer new insight. But she stressed that more study is needed.

“Understanding the distracted driving issue is an evolving process, and this study is but one step in that process,” she said. “We believe it’s a useful step, and we’re eager to see what other studies may find.”

The study’s results are being published during National Distracted Driving Awareness Month. Numerous agencies, including the Texas Department of Transportation (TxDOT), are sponsoring public awareness campaigns to highlight the dangers of driving distractions, particularly those associated with cell phone use.

Another TTI study now underway is examining 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 include a look at which demographic groups are most affected by the distracted driving issue, TTI said.