In a previous post, we discussed the new law in Illinois that prohibits cellphone use while driving. Under the law, drivers are not allowed to do anything that involves holding their cellphone in their hand anytime they’re on the road.

This law represents an important step towards encouraging more responsible and attentive driving on our streets. However, these restrictions may not go far enough.

Hands-free calling technology has often been lauded as a safe alternative to making a call on a hand-held phone call while driving. The idea is that having both hands on the road reduces distraction–which is true.

However, distracted driving is defined as anything that takes your hands off the wheel, your eyes off the road or your attention away from driving. Making a hands-free call while driving is still dangerous, because it actually takes more of your attention away from driving than having a conversation with a passenger in your car. Here’s why:

Not all conversations are created equal

Imagine you and your brother are driving down the freeway, discussing the latest Woody Allen movie. Out of nowhere, a minivan to your left darts into your lane. You swerve into the shoulder and narrowly avoid a crash. In this situation, having your conversation partner in the passenger seat is an advantage, because you both have the same vantage point. You both notice the careless driver at the same moment. You abruptly halt the conversation simultaneously. He yells “watch out!” as you reflexively weave out of the way.

Now let’s imagine the same situation, only this time, your brother is at home. When the minivan cuts into your lane, your brother doesn’t see this and continues talking. Your brain’s instinctive reaction is to attempt to pay attention to both events at once. Unfortunately, as humans, we’re incapable of doing this. This simple change in variables puts you at higher risk of a crash.

This may sound unlikely. You may be telling yourself you’re more attentive than this. But the numbers speak for themselves. Drivers who talk on the phone hands-free for just 50 minutes a week are five times as likely to get into an accident compared to drivers who don’t talk on the phone at all while driving.

Distracted driving is a growing problem in our country. It’s important to stay present while driving. The decision to postpone your phone call until you get home could be life changing.