Long driving hours have a potential of causing fatigue, which is known as a contributing factor for collisions. This paper examines the influence of bus operator driving hours on the occurrence of preventable collisions by employing data from a questionnaire survey, incident reports, and operator schedules to evaluate the correlation between driving hours, amount of sleep, and operator involvement in collisions. The results of the analysis of collision occurrences in relation to operator schedule show a discernible pattern of an increased propensity of collision involvement with an increase in driving hours. Based on the fatigue analysis, drivers involved in collisions were found to be overrepresented in the red fatigue condition, i.e., fatigue scores higher than fatigue tolerance level. View full report.