New research says that using voice-activated systems such as Apple’s Siri or Microsoft’s Cortana while driving causes mental distraction that can last nearly half a minute after use.

Researchers found that potentially unsafe levels of mental distraction can last for as long as 27 seconds after completing a distracting task in the worst-performing systems studied. At the 25 MPH speed limit in the study, drivers traveled the length of nearly three football fields during this time. When using the least distracting systems, drivers remained impaired for more than 15 seconds after completing a task.

“Drivers should use caution while using voice-activated systems, even at seemingly safe moments when there is a lull in traffic or the car is stopped at an intersection,” said Beth Mosher, director of public affairs for AAA Chicago. “The reality is that mental distractions persist and can affect driver attention even after the light turns green.”

Rated on a five-point scale

The researchers discovered the residual effects of mental distraction while comparing new hands-free technologies in ten 2015 vehicles and three types of smart phones. The analysis found that all systems studied increased mental distraction to potentially unsafe levels. The systems that performed best generally had fewer errors, required less time on task and were relatively easy to use.

The researchers rated mental distraction on a five-point scale. Category one represents a mild level of distraction and category five represents the maximum. AAA considers a mental distraction rating of two and higher to be potentially dangerous while driving.

The best performing system was the Chevy Equinox with a cognitive distraction rating of 2.4, while the worst performing system was the Mazda 6 with a cognitive distraction rating of 4.6. Among phone systems, Google Now performed best with a distraction rating of 3.0, while Apple Siri and Microsoft Cortana earned ratings of 3.4 and 3.8.

Sending texts significantly increased distraction

Using the phones to send texts significantly increased the level of mental distraction. While sending voice-activated texts, Google Now rated as a category 3.3 distraction, while Apple Siri and Microsoft Cortana rated as category 3.7 and category 4.1 distractions.

“The massive increase in voice-activated technologies in cars and phones represents a growing safety problem for drivers,” continued Mosher. “We are concerned that these new systems may invite driver distraction, even as overwhelming scientific evidence concludes that hands-free is not risk free.”

Previous AAA Foundation research established that a category 1 mental distraction is about the same as listening to the radio or an audio book. A category 2 distraction is about the same as talking on the phone, while category 3 is equivalent to sending voice-activated texts on a perfect, error-free system. Category 4 is similar to updating social media while driving, while category 5 corresponds to a highly-challenging, scientific test designed to overload a driver’s attention.

Over the last two weeks, AAA has used the findings to continue our collaborative work with policymakers, safety advocates and manufacturers to improve the safety of future technology.

“Developers should reduce mental distractions by designing systems that are no more demanding than listening to the radio or an audiobook,” continued Mosher. “Given that the impairing effects of distraction may last much longer than people realize, AAA advises consumers to use caution when interacting with these technologies while behind the wheel.”

For the full report see: http://newsroom.aaa.com/2015/10/new-hands-free-technologies-pose-hidden-dangers-for-drivers/