Effects of insomnia on risky driving behavior among bus drivers: The mediating effect of mental health

Abstract

Crashes caused by problems with bus drivers’ physical and mental health have increased in frequency in recent years. Insomnia, a common type of sleep problem, has significant positive relationships with both crash risk and mental health problems, especially anxiety and depression, which are themselves associated with driving behavior. However, few studies have conducted analysis on sleep-related problems and mental health exclusively on bus drivers, nor on how these problems influence driving performance. Thus, this study explored the effect of insomnia and mental health on bus drivers’ risky driving behavior and evaluated the interaction of four variables: insomnia, anxiety, depression, and risky driving behavior. The survey-based investigation was conducted in a bus company in Suzhou, China, with 1,295 bus drivers participating. Insomnia, anxiety, and depression were self-reported based on professional mental health scales and risky driving behaviors were measured by the Driver Behavior Questionnaire. Two mediation models and a chain mediation model were developed to examine relationships among the bus drivers’ insomnia, anxiety, depression, and risky driving behavior. Results revealed that (a) bus drivers less than 31 years old, drivers with more than 11 years’ experience driving buses, and those with crash and violation involvement within three years demonstrated more severe degrees of insomnia, anxiety, depression, and risky driving behavior; (b) there were significant positive correlations and interactions among the four variables. Results specifically related to the interaction among variables include findings that (a) anxiety mediated between insomnia and risky driving behavior; (b) depression mediated between insomnia and risky driving behavior; and (c) anxiety affected bus drivers' risky driving behavior primarily though depression. The findings in this study indicate the importance of regular physical and mental health examination of bus drivers and suggest that interventions focused on insomnia and mental health problems may be helpful to reduce risky driving behaviors of bus drivers both directly and indirectly.