Effects of physical fatigue on construction workers' visual search patterns during hazard identification

Physical fatigue is a frequent factor in construction workplaces that threatens workers' safety. This study examines whether fatigue alters visual search patterns adopted by workers during hazard identification, thereby affecting identification performance. Subjects (n=24) were exposed to four physical activity levels (nonfatigue, low fatigue, medium fatigue, and high fatigue) and then performed hazard identification tasks in a panoramic virtual reality context, with their search patterns being reflected by eye-movement metrics. The results show that physical fatigue significantly impacted the visual search patterns, with workers allocating less attention to hazardous areas and being less engaged in searching. These visual characteristics correspond to poorer hazard identification accuracy. Further, the degree of influence increased with fatigue levels. The findings could extend the knowledge of the relationship between physical fatigue and safety. They could also uncover the reasons inherent in workers' inability to identify hazards due to physical fatigue, which could provide insight for the industry to cope with the disruptions to safety posed by physical fatigue.