In California, and in several other states in the nation, it is illegal to use a hand-held cell phone while driving. Many states passed this legislation as a way to minimize the surprising number of injuries and deaths caused by distracted driving car accidents every year. Using a hand-held cellular device while behind the wheel causes a significant amount of cognitive, manual and visual distractions.

Instead of risk getting a driving violation by using a hand-held phone while driving, some motorists use hands-free devices. Businesses market these cellphones as a safe alternative to hand-held devices as they do not require drivers to take their hands off the steering wheel or eyes off the road. They do, however, cause cognitive distraction, which may be more dangerous than some people think.

Study: Hands-free vs. hand-held cell phones

A study published in AAA looked at the amount of cognitive distraction caused by certain forms of driver distraction. Researchers asked participants to engage in certain tasks while operating a simulator vehicle, as well as a car set up with monitoring devices. These tasks included the following:

  • Listening to an audiobook
  • Listening to the radio
  • Talking with a passenger in the car
  • Maintaining a conversation using a hand-held cellphone
  • Maintaining a conversation using a hands-free cell phone
  • Composing a message using voice-activated technology

Researchers measured drivers’ heart rate, brain activity, eye movement and response time.

The results

They found that while hand-held cell phones were more distracting than hands-free devices, the difference was minimal. Hands-free cell phones still acted as a significant source of cognitive distraction. Cognitive distraction occurs when motorists focus on something other than driving, leaving moments where drivers are unable to quickly respond to certain hazards. These include bad weather conditions, objects in the road, pedestrian crosswalks, traffic signals and other drivers. It is safest to put away all distractions while driving and focus on the road ahead.