An Assessment of Commercial Motor Vehicle Driver Distraction Using Naturalistic Driving Data

Objective: This study analyzed naturalistic driving data from commercial trucks (3-axle and tractor-trailer/tanker) and buses (transit and motorcoach) during a 3-month period. Methods: The data set contained 183 commercial truck and bus fleets comprising 13,306 vehicles and included 1085 crashes, 8375 near crashes, 30,661 crash-relevant conflicts, and 211,171 baseline events. Study results documented the prevalence of tertiary tasks and the risks associated with performing these tasks while driving. Results: Results indicated the odds of involvement in a safety-critical event differed as a function of performing different cell phone-related subtasks while driving. Although the odds ratio for talking/listening on a cell phone while driving was found to not significantly increase the likelihood of involvement in a safety-critical event, other cell phone subtasks (e. g., texting, dialing, reaching) were found to significantly increase the odds of involvement in a safety-critical event. Conclusions: The results suggest that cell phone use while driving should not be considered a simple dichotomous task (yes/no). Consideration should instead be made for a set of discrete cell phone subtasks that are each associated with varying levels of risk. Several hypotheses are presented to explain why cell phone use while driving was found to not increase the likelihood of involvement in a safety-critical event.