Fatigue and Distraction in Occupational Light Vehicle Drivers

Abstract

Occupational drivers are a unique subset of the driving population, as driving per se is not their primary job duty, but can nonetheless encompass a large portion of their working day. These occupational drivers make sales calls to various clients and other business entities throughout the day, and often use fleet vehicles as a critical component of business. The purpose of this research was to conduct an analysis of naturalistic data to better understand the behaviors of occupational drivers. Naturalistic data were collected by Lytx, a driver risk management company, over a 3-month period. Supervisors in utilities and service organizations were the target vehicles in the analyses, as these employees had a driving profile that involved travel to site locations throughout the working day (e.g., they engaged in daily driving to various locations over the course of the day). The final data set contained 312,672 naturalistic driving safety-critical events (SCEs) and spurious baselines (BLs) reduced for driver behaviors and tasks. Overall, non-driving-related distraction tasks were uncommon in spurious BLs and SCEs (only 2.26% of spurious BLs and 2.51% of SCEs had at least one distraction task observed). The task most frequently observed in the spurious BLs and SCEs was any task using a handheld cell phone, a task that included several cell phone subtasks. Observations of drowsy or falling asleep behaviors were rare (less than 0.01% of the SCEs and spurious BLs had observable signs of drowsiness). However, the odds of driver drowsiness for an SCE that did not include a confidence interval of “1.0” were higher than for spurious BLs (odds ratio estimate = 6.59, 95% confidence interval = [3.21, 13.57]). Future research should include an analysis of risk, distraction occurrence, and driver drowsiness for different types of occupational drivers. Also, future research should investigate the impact of safety policies, practices, and culture on SCE occurrence.