Fatigue is one of the causes of transportation accidents, characterized by reduced physical and mental performance resulting in reduced alertness due to drowsiness. The present study was to determine the risk factors and contributing factors of fatigue suffered by heavy equipment operators. The study was conducted at three coal mining sites in Kalimantan (2 areas in East Kalimantan and 1 area in South Kalimantan) involving 353 heavy equipment operators who work in shifts. It was found that fatigue complaint is higher by older age, longer work, and work at shift 3 (night time). The fatigue is mostly complained by dump truck (hauling part) operators which was influenced by work-related factors (work posture, job variety, workload, vigilance) and non-work related factors (terrain or mine risk area, lack of lighting at night, and route track which is always changed). Another factors related with socio-psychological factors, either related with job or working environment, such as adequacy of rest time, remuneration system, leave system, and insecure career. It is concluded that in general the fatigues were increased as the worker ages were older and longer duration of work, with higher fatigues were suffered at shift 3. Generally, reduced reaction time among shift 3 workers is higher than that those of daytime shift.