Hands-free danger: study shows why even speakerphone usage impedes driving ability

Smartphones make it so easy to keep connected with the world around us that it can be difficult to give them up, even for a few moments – how many times have you snuck a peek at your phone in a movie theater, at the kitchen table, or even in a work meeting? Most of us know by now, though, that smartphones and driving just don't mix, and we're resigned to putting our phones down while behind the wheel – all in the name of safety. But even if we know better than to be touching and looking at our phones, isn't hands-free operation OK – keeping our hands on the wheel and eyes on the road? A new study adds to the voices saying “no,” and offers some new insight into just why even hands-free phone usage can be so distracting.

A study conducted by a team of psychologists at the University of Sussex in England investigates one reason why conducting hands-free calls on your phone while operating an automobile still manages to impair driver performance and slow down reaction times.

The group focused on the effect of how our brains process imagery, and the ability for a conversation to evoke such images.

For instance, you might be on the phone with your roommate when he asks what you did with last night's leftovers. As you try to remember where you put them, the imagery-processing part of your brain attempts to visualize your apartment – and in doing so, that takes away processing abilities that would otherwise be used to watch the road ahead of you.

On average, drivers engaged in such a conversation took a little less than a second longer to respond to on-road events than those who were driving distraction-free. And while that may not seem like much, an additional second can add an extra 100 feet to the distance it takes to stop when you're driving at 70 mph.

Maybe save the phone calls for when you've finally reached your destination?

source: University of Sussex via BBC