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Why The FMCSR Allows The Use Of Hands-Free Cell Phones – Part Two

On Behalf of | Jun 30, 2021 | Firm News

Part two of this blog discusses additional studies that compare the use of hand-held and hands-free cell phones, and their effect on a driver’s likelihood of being involved in an accident.

Mobile Phone Use – Effects Of Handheld And Handsfree Phones On Driving Performance

While the two studies addressed in the last blog were naturalistic studies, this study dealt with simulated driving situations. This study considered the effects of dialing and conversation while driving through urban and rural environments. The study found that performance on a peripheral detection task while driving was impaired if an individual was dialing and/or talking on either a hand-held or hands-free device. It attributed this to an increase in the driver’s mental workload. The study then broke down the effects that dialing and conversation had on the lateral position deviation of the CMV and the change in speed. Overall, the study found that driving performance was rated better for hands-free than for hand-held devices.

The Prevalence Of And Crash Risk Associated With Primarily Cognitive Secondary Tasks

This study used another large-scale naturalistic driving database but considered the risks of primarily cognitive secondary tasks. The results of the study indicated that primarily cognitive secondary tasks are not associated with an increase in accidents. It noted that drivers are actually alert and attentive. A big part of this analysis including analyzing the cognitive secondary tasks when a driver was interacting with a passenger. Presumably, because using a hands-free device is a similar interaction, the same conclusion was made regarding talking or listening on a hands-free cell phone. Ultimately, this study concluded that there are no increased risk when talking/listening on a hands-free cell phone.


While best practice may be for drivers to refrain from using cell phones while driving all together, hands-free devices are permitted by the FMCSR. The studies discussed in parts one and two of this blog show that the use of hands-free devices does not increase the risk of accident. The driver distractions that cause an increase in risk of accidents are primarily associated with hand-held devices where a driver is reaching for and dialing on their cell phone


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