Hands Free Cell Phones Don't Solve Driver Distraction

The number of wireless phone subscribers in the U.S. is constantly growing and studies have linked the use of wireless phones while driving to an increased number of automobile crashes. Across the U.S. and in other countries, numerous efforts are underway to pass legislation that allows only hands-free wireless phone use while driving. This push is based on the assumption that hands-free phones reduce the visual-manual demands of wireless phone use and are safer since the driver can keep both hands on the wheel and both eyes on the road.

However, hands-free wireless phones most commonly allow only for hands-free conversation; accessing the phone, dialing, and hanging up still involve physical contact with the phone as well as directed glances toward it. Drivers are still temporarily distracted during these times and are potential opportunities for automobile crashes.

The National Highway Traffic Safety Administration (NHTSA) recently conducted a driving simulator study to examine the effects of phone interface type on driving performance and drivers' ability to perform phone tasks. In theory, voice dialing should relieve the visual demand related to dialing a wireless phone while driving. Unfortunately, if the voice recognition capability of the hands-free interface is poor, placing a call may actually take longer than it would with manual dialing, thus increasing the length of time a driver must focus on the phone and not the road in front of them.

NHTSA conducted the study using the National Advanced Driving Simulator (NADS). Results showed that in most cases participants overestimated the difficulties linked with hands-free phone interfaces. In general, drivers considered the hand-held interface to be most difficult to use, followed by the headset hands-free and voice dialing hands-free interfaces, respectively. However, significant differences among interfaces were evident for dialing and hanging up. The hand-held interface was associated with the fewest dialing errors and significantly faster dialing times than the two hands-free interfaces.

A substantial portion of the 163 million cell phone subscribers use their wireless phones while driving, at least occasionally. According to a survey by the National Highway Traffic Safety Administration (NHTSA), at any given time, an estimated 3 percent of those driving passenger vehicles on America's roadways are talking on hand-held wireless phones (NHTSA, 2001). The 2000 Motor Vehicle Occupant Safety Survey estimated that 73 percent of drivers who said they usually have a wireless phone in their vehicle with them use a hand-held phone, while 22 percent use hands-free equipment (NHTSA, 2001). The crash related effects of wireless phone use while driving is a controversial issue, and has been under public scrutiny in recent years.

Rae Tyson, a spokesperson for NHTSA had this to say "We've evaluated and come to the conclusion that hands-free use is just as risky or perhaps riskier than hand-held phones because it's the cognitive distraction that can compromise driving."

(Source: NHTSA)