Commercial Drivers' Health: A Naturalistic Study of Body Mass Index, Fatigue, and Involvement in Safety-Critical Events

Objective: To explore the relation of commercial truck drivers' body mass indexex (BMI) to fatigued driving episodes and involvement in safety-critical events. Methods: One hundred and three professional truck drivers participated in a long-term naturalistic (on-road) driving study whereby vehicle motion data as well as video of the driver and driving environment were gathered continuously. This data set was analyzed to identify safety-critical events as well as fatigued driving episodes using two independent measures of fatigue. Odds ratio analyses were then performed to explore the relative risk of driving while fatigued and involvement in safety-critical events based on driver's BMI classification (obese versus non-obese). Results: Results indicated that of the 103 participating truck drivers, 53.4 percent were obese based on BMI. Odds ratio calculations revealed that obese individuals were between 1.22 (CI = 1.03-1.45) and 1.69 times (CI = 1.32-2.18) more likely than non-obese individuals to be rated as fatigued based on the two measures of fatigue. Other analyses showed that obese individuals were at 1.37 times (CI = 1.19-1.59) greater risk for involvement in a safety-critical event than non-obese individuals. Finally, one of the fatigue measures showed that obese individuals were 1.99 times (CI = 1.02-3.88) more likely than non-obese individuals to be fatigued while involved in an at-fault safety-critical incident. Conclusion: The results of this study support other research in the field of health and well-being that indicate a link between obesity and fatigue, which is a major safety issue surrounding commercial motor vehicle operations given the long hours these drivers spend on the road.