Even hands-free, phones and their apps cause dangerously distracted driving

This article was originally featured on The Conversation.

Do you ever use your cellphone while driving? Don’t feel too guilty about saying yes–nearly 60% of drivers admit to using their phone in hands-free mode while driving.

But don’t become complacent either. Using your cellphone in hands-free mode while driving is not a perfectly safe activity, despite the impression you might be getting from laws, marketing messages and the behavior of people around you.

Fatal crashes caused by driver distraction have not gone down significantly over time: Distraction caused 14% of fatal crashes in 2017 and 13% of fatal crashes in 2021. Given that these numbers are calculated based on police-reported crashes, many experts believe the actual number of crashes caused by driver distraction is much higher. For example, real-world crash data from teens indicates that 58% of their crashes are due to driver distraction.

I am a human factors engineer who studies how drivers interact with technology. I see a gap between what people are told and what people should do when it comes to using your cellphone behind the wheel.

Hands-free calling

Most U.S. states ban hand-held cellphone use while driving but allow hands-free devices. However, hands-free devices are still distracting. Talking on a hands-free phone and driving is multitasking, and humans are not good at doing two cognitively demanding tasks at the same time.

For example, having a phone conversation in hands-free mode while driving causes you to stop looking out for hazards on the road and gets you into more close calls where you slam on the brakes than if you were not on the phone.

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These detrimental effects last even after you end your call. There is a hangover effect: You can remain mentally distracted nearly 27 seconds after you finish using your cellphone. At 65 miles per hour, you’ve traveled nearly half a mile in 27 seconds.

Third-party apps

Third-party apps that connect your smartphone to your car’s interface, such ass Apple CarPlay and Android Auto, encourage you to use your phone in hands-free mode while driving. You can control things like music, navigation, text messaging and phone calls using voice commands and the car’s interface. IPhone users can connect their phones to more than 800 car models and Android phone users more than 500 models.

But is using these third-party apps while driving safe? Fifty-three percent of people say that if carmakers put the technology in vehicles, they must be safe. Though these third-party apps make cellphone use hands-free, they unintentionally cause you to look away from the road for dangerous amounts of time and they slow your reaction time.