Driving while holding a cell phone to talk, and even worse, texting, is extremely dangerous. In fact, it's illegal in many states. But what about hands-free devices that allow drivers to keep their eyes on the road while taking care of digital business?
It turns out that these hands-free systems may not be safe at all, because they can distract drivers just as much, maybe even more in some cases, than hands-on activities. That’s according to a recent study from University of Utah psychology professor David Strayer, on behalf of the AAA Foundation for Traffic Safety. Strayer and his colleagues found that drivers' mental workloads increased while using advanced, voice-controlled systems. That slowed driver reaction times and could make them miss things in front of them, including pedestrians and stop signs.
(Driver on left is wearing test helmet to measure reactions.)
I’m no researcher, but the study is consistent with my own experiences. I’ve seen too many people do really clumsy things while using a cell phone equipped with an ear piece and microphone to doubt the conclusion. Yes, their hands were free, but their brains weren’t. When a person's attention span is divided, something has to give. Sure, some people's brains are probably wired differently than mine, and they may be capable of multitasking safely while driving. But they're probably in the minority.
Things that don’t seem very distracting can also causes problems. A recent University of San Diego study, for example, shows that when you're subjected to other people’s conversations on cell phones you're much more distracted than if you had listened to a conversation between two people in the same room or elevator or train.
But getting back to the voice-activated devices: Strayer's researchers measured driver brainwaves and eye movements to see what happened when they performed different tasks, such as listening to the radio and talking on the phone while driving. The conclusion:
"Moreover, compared to the other activities studied (e.g., listening to the radio, conversing with passengers, etc.) we found that interacting with the speech-to-text system was the most cognitively distracting. This clearly suggests that the adoption of voice-based systems in the vehicle may have unintended consequences that adversely affect traffic safety."
In other words, using those devices is dangerous and could get you and other people killed or badly injured.
Not surprisingly, the people who have the most to gain by placing these devices in cars—the auto and electronics device makers—have found all kinds of reasons to quibble about the results. I still think keeping hands-free devices out of cars is the safest bet. What's really lost if the devices are banned? Time online. But countless lives could be saved.