The Texas A&M Transportation Institute says its tested drivers took about twice as long to react to roadway situations as they did when they weren’t texting on a handheld smartphone, regardless of whether they used their hands or voice to read, create and sent texts.
The tested drivers looked at the road ahead less frequently as well, the study found. Use of a voice-to-text application did not help drivers keep their eyes on the road compared with straight manual texting.
The drivers operated an instrumented test vehicle (pictured).
Drivers felt safer using the study’s voice-to-text applications — the iPhone’s Siri and the Andriod system’s Vlingo — but researchers found driving performance suffered equally with both methods of text messaging.
The Texas A&M researchers found that manual texting required slightly less time than the voice-to-text method, but the drivers’ performance was not affected.
Drivers were able to stay in their lanes while texting on a straight roadway, but the researchers noted “many occasions” in which the drivers began to veer out of their lanes on turns and curves.
The Siri application produced fewer errors than the Vlingo and manual methods, but required more back-and-forth interaction with the software. Siri is a preinstalled feature of the iPhone, while Vlingo is a third-party app.
The researchers said it would be interesting to study why test participants felt the Siri was the safest method of texting & driving, a conclusion not supported by the data.
“These results have immediate implications for improving our understanding of … the potential safety improvements of using voice-to-text options,” the study said.
“Texting is not an activity that should be coupled with driving,” the study concluded.
The distracted driving study, called “the first of its kind,” was based on the performance of 43 research participants driving an actual vehicle on a closed course.
Drivers had to certify that they were “very familiar” with sending and receiving text messages on a smartphone. 72 percent of the drivers admitted to texting & driving, which is legal in Texas. 77 percent said texting while behind the wheel was unsafe.
Texting by voice was legalized in California last year via a bill that was billed as the Freedom to Communicate Act. That exemption to the state’s texting & driving would be removed under distracted driving legislation currently before the Assembly.
Some vehicle manufacturers tout voice-controlled texting as safety-minded features in their Internet-connected dashboard systems. Separate studies have looked at the safety of those in-dash systems.
Read results of the voice-to-text driving study (PDF).