Many people mistakenly believe that they are capable of multitasking. While they may complete two tasks at the same time, their performance at each suffers. The reason is that the human brain isn’t capable of doing true multitasking. Instead, it switches back and forth between tasks and requires additional time to get back up to speed each time it does a switch. Therefore, it takes more time to do both tasks together than separately.
This means that the multitasking driver will react more slowly to traffic events. In addition, very little if any mental focus is given to anticipating dangers. An example of this is seeing a ball bounce across a street without anticipating the child that chases after it. This effect of mental multitasking while driving, also called cognitive distraction, is why hands free cell phones do not solve the problem of distracted driving.
Cognitive distraction also causes a phenomenon called “inattention blindness.” The brain can only process so much information at a time. When it’s overloaded, it fails to process all of it. For the driver using a hands free cell phone, this means his eyes become partially blind to the road scene ahead. Although his brain is aware of the road, details such as road signs, traffic lights, and even cars fail to register.
According to the National Safety Council, drivers using either handheld or hands free cell phones fail to see up to 50% of the driving environment in front of them, even though their eyes are looking directly at it. In addition, their field of view narrows.
The insidious aspect of inattention blindness is that the driver has no awareness of its occurrence. The person engaging in cell phone use while driving will confidently believe the way ahead is clear when in fact it isn’t. This phenomenon also occurs to pedestrians using cell phones who walk into telephone poles even though their eyes are looking straight ahead.
Cognitive distraction isn’t limited to cell phone use. When your mind is split between driving and something else such as daydreaming, deep thoughts, or a podcast, you are a distracted driver.