Efforts by federal officials prohibiting all interstate and haz-mat truckers from texting while driving, along with many state having such laws for all drivers, may do little for safety on the roadway, based on new research.

A study conducted by the Texas A&M Transportation Institute has found evidence that voice-to-text smartphone applications while driving are no safer over manual texting when behind the wheel.

The study is based on the performance of 43 research participants driving an actual passenger vehicle on a closed course.

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, 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, and also noted how long it took for the drivers to respond to a light which came on at random intervals during the exercises.

Among the major findings researchers discovered driver response times were significantly delayed no matter which texting method was used. In each case, drivers took about twice as long to react as they did when they weren’t texting. TTI says, “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 study also found the amount of time that drivers spent looking at the roadway ahead was significantly less when they were texting, no matter which texting method was used 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.

Ironically, drivers report they 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.

Christine Yager, a TTI Associate Transportation Researcher who managed the study, says the findings offer new insight, but only a part of the knowledge that’s 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. “We believe it’s a useful step, and we’re eager to see what other studies may find.”

Previous research into texting while driver have evaluated manual versus voice-activated tasks using devices installed in a vehicle, but the TTI analysis is the first to compare voice-to-text and manual texting on a handheld device in an actual driving environment.