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This studied situational awareness (SA) in relation to induced mental and physical workloads while performing work on a real construction site.

They drew on Endsley’s three-level model of SA, being:

Level 1: perception of elements in the current situation; said to be the “most fundamental component of SA”. Given that attention is selective, things can be missed at this stage.

Level 2: comprehension of the current situation; the importance of the situation is gained through the combination, interpretation, and retrieval of information and this varies between people and mental models.

Level 3: the projection of future status; this level combines levels 1 and 2, where people predict possible future conditions and events which allows people to prospectively select appropriate actions to meet future goals.

Participants (either current construction workers or future occupants of the constructed building who were inspecting the building) were required to identify site signage and fire-fighting equipment, comprehend the meaning and content of the signs (locations, colours, shapes etc.). To simulate high physical load, subjects walked up and down stairs between sessions, whereas mental load was induced via word recall tests.

Results:

Findings indicated that a worker’s level 2 SA (comprehension of the site surroundings) is always statistically lower than their level 1 SA perception of the surroundings. That is, workers see things far more often than they see *and* comprehend them.

Workers’ SA significantly decreased when given a mental workload, leading authors to state that “In stressful work conditions, such as mental workload, it is difficult to efficiently gather information, and workers are more likely to succumb to attention tunneling (Endsley 2016), or a narrowing of attention during concentration” (p8).

In contrast to mental workload which reduced SA, physical workload in this study (which was noted to be at a load similar to their regular work) didn’t significantly affect workers’ SA. Authors discussed how people naturally tended to slow their movements when experiencing excessive physical loads, thereby likely offsetting some of the negative impact of physical demands on their SA. Expectedly, the faster people walked the more difficulty they had with perceiving and comprehending the environment due to their lower attention capacity.

Authors then discussed the applicability of the findings to safety management in construction. They state the importance of increasing the ease of comprehensibility of safety signs and equipment. Regarding the impact of mental workload on workers’ SA, they suggest “more careful supervision”, better hazard perception and risk comprehension training and focusing on “altering critical behavior among workers” (p8).

Personally, I don’t really think that these recommendations are the core learnings from the results; but each to their own.

More than indicating the need to retrain people or alter behaviour, my view is that these findings further support the challenges people have with navigating and comprehending complex environments with a multitude of stressors. It also supports the constraints around local rationality that people face. Thus, in my view, these findings better support a view of redesigning the work environment to better suit human perception and comprehension, altering the work pace (e.g. work intensification), stretched resources and work pressures and other largely systems factors. Again, in my view, this is further supported by other research indicating somewhere upwards of 40% of fatal workplace incidents involve design as a factor, or construction site design and layout, respectively.

More difficult? Yes. But placing undue pressures on workers to get the work done but then expecting them to somehow magically know exactly when to slow down to identify and comprehend sometimes near “invisible” workplace cues is unreasonable and unsustainable.

** Note. I’m not discounting the importance of supervisors being present to supervise, support and coach, nor enhancing hazard recognition and comprehension, but rather the constant focus on trying to change workers instead of improving workplace design factors, e.g. Reason’s changing the conditions under which people work rather than the human condition and all that jazz.

Authors: Siyeon Kim, Heerim Lee, Sungjoo Hwang, June-Seong Yi & JeongWook Son, 2021, Construction Management

Study link: https://doi.org/10.1080/13467581.2021.1908899

Link to the LinkedIn article: https://www.linkedin.com/pulse/construction-workers-awareness-safety-information-load-ben-hutchinson