Investigating the impact of physical fatigue on construction workers’ situational awareness

Abstract

Construction is a physically demanding occupation that requires workers to exert themselves when executing tasks. Many construction tasks involve manual handling, making fatigue part of construction workers’ everyday experience. Physical fatigue has been shown to impact worker safety as it affects workers’ cognitive ability to process hazard information. Studies have shown that when workers’ situational awareness diminishes, there is a higher tendency for workplace accidents. However, most studies measured physical fatigue using subjective scales which could be impacted by cognitive bias and a lack of quantitative values for measuring situational awareness. Thus, this study tracked individuals’ physical fatigue in real-time using a wearable sensor and assessed fatigue impact on participants’ Hazard Recognition Performance (HRP) and Safety Risk Assessment (SRA). Seventeen participants were recruited for this study and a validated instrument was used to assess their HRP and SRA. The wearable sensor showed that the participants experienced moderate-to-high intensity physical fatigue which was validated by a significant change in their heart rate (HR) and heart rate variability (HRV). The findings indicate that fatigue caused a significant reduction in the participants’ HRP (>12 % reduction) and SRA (>28 % reduction). Based on the results, the participants’ situational awareness had reduced significantly when their HR, HRV, and/or Rating of Fatigue (ROF) were correspondingly 135.20 bpm, 35.8 msec, and/or 9, while HR and ROF independently explained about 32 % of the variability of the HRP. This study empirically confirms the critical role of fatigue in situational awareness research and shows that wearable sensors could play a vital role in fatigue and hazard recognition assessment.