Background and purpose: Occupational fatigue is one of the main problems in work environments. Investigation of different aspects of occupational fatigue in drivers is of great benefit in reducing the level of road accidents.

Materials and methods: We conducted a cross-sectional study in 420 drivers of heavy vehicles. Data was collected using a demographic and job information questionnaire and Swedish Occupational Fatigue Inventory (SOFI). T-Test and multivariate linear regression were applied for data analysis.

Results: The average daily driving hours was found to be significantly associated with all dimensions of fatigue except for lack of energy (P<0.05). Also, significant relations were found between parameters such as average hours of rest, smoking and sport activity and all dimensions of fatigue (P<0.05). Adjusting for confounding variables by linear regression model, sport activity displayed the greatest effect on reducing the level of fatigue.

Conclusion: Occupational fatigue in drivers has close relations with their habits and occupational activities. Modifying some negative behaviors such as smoking, inactivity, lack of attention to rest and continues driving can play major roles in incidence of occupational fatigue.