Handheld and Hands-Free Cell Phone Use Amongst Drivers with Hands-Free Technology

To address safety concerns of handheld phone use while driving, several hands-free cell phone technologies have been developed for use while driving. The current study investigated drivers’ use of these hands-free cell phones. The naturalistic driving data were collected in 2011 from 204 participants who reported using a cell phone while driving at least once per day. Drivers drove their own vehicles, which had been instrumented for data collection, and participated on average for 31 days. Drivers also provided cell phone records, which were overlaid with the naturalistic data and used to determine when cell phone use occurred while driving. The data were first analyzed in the NHTSA study titled “The Impact of Hand-held and Hands-free Cell Phone Use on Driving Performance and Safety-Critical Event Risk.” In the current study, it was found that drivers with hands-free cell phones were observed to use a hand-held phone more frequently than hands-free phones in call initiation subtasks. Call initiation subtasks on a handheld phone often involve several visual-manual components that require a driver to look away from the forward roadway, and therefore, it is concerning that drivers are choosing a handheld phone over a hands-free phone for this task. Use of a hands-free cell phone did change in certain environmental conditions, but no demographic conditions were found to be associated with changes in hands-free cell phone use.