Abstract
Construction site accidents can be reduced if hazards leading to accidents are correctly and promptly detected by employees. Proactive safety measures such as safety perception and safety detection capability of employees play an important role in improving the safety performance. This study was initiated by three research questions related to (1) the measurement indicators of employees’ cognitive load in recognizing safety hazards; (2) site condition factors (e.g., brightness) that can affect subjects’ cognitive load; and (3) the quantification of the effects of these site factors on cognitive load. An eye-tracking experimental approach was adopted by recruiting a total of 55 students from construction management or other civil engineering disciplines to visually search hazards in 20 given site scenes. These site scenes were defined by a combination of three different categories, namely distinctiveness of hazards, site brightness, and tidiness. Quantitative measurements of experimental participants’ visual search patterns were obtained from data captured by the eye-tracking apparatus. Based on metrics related to experimental participants’ fixation, visual search track, and attention map, these measurements were computed to evaluate participants’ cognitive load in detecting hazards. Descriptive statistical comparisons analyzed these metrics under predefined categories of site conditions, i.e., distinctness versus obscurity/blurriness, brightness versus darkness, and tidiness versus messiness. The findings revealed that distinct site conditions reduced participants’ time in saccades to search hazards but did not improve the accuracy rate of first fixation; messy sites with disorganized items increased participants’ cognitive load in detecting hazards in terms of all five measurement items (i.e., accuracy rate of first fixation, fixation count, intersection coefficient, fixation duration, and fixation count in the attention center); the effect of increased brightness on-site needs further studies to determine the optimal balance of brightness level and allocation. Recommendations based on the findings were provided to enhance safety education in terms of site hazard distinctiveness, brightness, and housekeeping best practice. This study extended a few prior studies of adopting eye-tracking technology for safety monitoring by evaluating the impacts of site conditions on participants’ cognitive load, which was linked to their hazard detection performance. The study provided insights for evaluating construction employees’ hazard detection capabilities to enhance safety education. Future work is proposed to evaluate employees’ safety hazard detection pattern under dynamic construction scenarios.
Highlights
Human errors are the main causal factor that contributes to up to 80% of all accidents across industries (Garrett and Teizer, 2009)
This study extended a few prior studies in adopting the eye-tracking technology for safety monitoring by evaluating the impacts of site conditions on participants’ cognitive load which was linked to their hazard detection performance
Excluding the ten student participants in the pilot study, another 55 students from civil engineering (CE) or construction management (CM) subjects were recruited for the formal experimental study
Summary
Human errors are the main causal factor that contributes to up to 80% of all accidents across industries (Garrett and Teizer, 2009). One of the major human factors affecting employees’ safety performance is the failure to perceive critical factors in a given environment in order to make correct predictions or decisions (Endsley, 1995). A better understanding of human factors’ effects in construction safety performance could enhance existing safety education, and further improve site safety performance. Attention failure is one of the major causes of construction accidents (Li et al, 2019). Prevention of construction employees’ attention failure plays an important role to enhance site safety. Existing measurements of construction employees’ hazard detection performance or other safety accountability using the questionnaire survey approach (e.g., Han et al, 2019b) could be prone to subjectivity. Limited investigation has been conducted using a more objective approach to test employees’ hazard detection performance, as well as relevant influence factors, e.g., the site condition, and the mental fatigue of site employees (Li et al, 2019), etc
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
