Abstract
BACKGROUND:
Frontline supervisors have the most frequent interactions with workers on construction projects. Although Supervisors’ Safety Leadership (SSL) is commonly practiced, its specific inter-relationship with workers’ safety violations remains unclear, especially when it comes to detailed interactions between supervisors and workers, such as supervisors’ safety coaching/safety controlling/safety caring against workers’ situational/routine safety violations.
OBJECTIVE:
This study aims to uncover the intrinsic relationship between SSL and safety violations from the perspective of construction workers with the help of mediating variables at both organizational and individual levels.
METHODS:
A questionnaire survey was conducted to test all hypotheses based on empirical data from 346 construction workers. The path coefficient of the fitted model was then analyzed, including associated mediating effects.
RESULTS:
Situational safety violations are directly affected only by safety caring (β= –0.161, p < 0.05), while routine safety violations are impacted only by safety coaching (β= –0.159, p < 0.05). SSL can influence different types of safety violations through differing mediators. In particular, safety coaching acts on individuals’ routine safety violations mainly through self-efficacy (β= 0.199, p < 0.01; standardized indirect effect = –0.121, 95% CI[–0.226, –0.024]); safety controlling is more oriented to influence individuals’ situational safety violations through group safety norm (β= 0.383, p < 0.001; standardized indirect effect = –0.091, 95% CI[–0.177, –0.036]); and safety caring further influences individuals’ situational safety violations mainly through safety motivation (β= 0.581, p < 0.001; standardized indirect effect = –0.263, 95% CI[–0.418, –0.146]).
CONCLUSION:
The research enhances existing knowledge by clarifying the complex relationships between supervisor behavior and safety outcomes, particularly from the perceptions of construction workers towards supervisors’ actions and leadership.
Keywords
Introduction
Construction accidents lead to around 60,000 fatalities annually worldwide, equivalent to one accident every nine minutes [1, 2]. The incidence of non-fatal injuries in the construction industry is nearly 30% higher than in other industries [3, 4], indicating a high incidence of both fatal and non-fatal injuries in this industry. The frequent and severe consequences of construction accidents (e.g., casualties) have led to continuous exploration of their causes. Workers’ safety violations are identified as one of the major contributors to construction accidents [5–7]. Suraji et al. [8], in their analysis of 500 construction accidents in the United Kingdom, attributed approximately 80% of these accidents to workers’ safety violations. Hinze and Rinker [9] also stated that more than 75% of construction accidents were caused by safety violations among the workforce. These violations are influenced not only by the work environment and tasks but also by the behavior of other staff in the same organization, especially managerial behavior [10–14]. Specifically, when managers demonstrate strong safety awareness and behaviors and effectively communicate them to workers, it significantly mitigates workers’ safety violations [7]. For managers, the ability to ensure safety and guide their subordinates towards common safety goals has been defined as “Safety Leadership” [15, 16]. Safety leadership provides an innovative research direction for the exploration of the safety behavior of workers, and some empirical studies have investigated its effectiveness in accident rate reduction [5, 17–19].
With the introduction of safety leadership, increasing attention has been paid to its impacts on workers’ safety violations. Due to the multi-layered structure of organizations and the varying roles and responsibilities of managers in the construction industry, there are different forms of safety leadership, each with varied influences on workers’ safety violations. Flin and Yule [20] divided the management structure of construction projects into three layers: the strategic layer, the tactical layer, and the frontline operational layer. The strategic layer generally comprises a senior management team led by a project manager [21]. The tactical layer usually contains middle managers (e.g., department heads of a construction project) [21]. The frontline operational layer consists mainly of the junior managers of construction projects, also known as “supervisors” [7, 23]. Supervisors have direct access to the frontline workers and supervise their daily production and operation behavior [21, 24]. Compared with middle and senior managers, supervisors play more critical roles in accident prevention, given their closest relationships and most frequent interactions with workers [21, 25–27]. However, the inter-relationships between the safety leadership of supervisors and workers’ safety violations remain unclear, particularly regarding the specific relationship between the different dimensions contained in both [7].
Based on the above description, this study aims to reveal the intrinsic relationship between SSL and safety violations from the perspective of construction workers. It intends to bridge the research gap in related theoretical systems and management practices from three aspects, in order to make more in-depth theoretical contributions and practical value. First, although existing literature has provided insights into the relationship between supervisors’ safety leadership and workers’ safety violations (or compliance) [28, 29], many studies have focused solely on SSL’s impact on safety violations [30–32]. This study, however, more comprehensively considers the three core dimensions of SSL: safety coaching and safety caring, characteristic of transformational leadership, and safety controlling, characteristic of transactional leadership [33, 34]. In addition, it incorporates two dimensions of safety violations: individuals’ routine safety violations and individuals’ situational safety violations [7, 35–37]. This multidimensional division not only demonstrates the varying impact of different types of SSL but also helps to explore the mechanisms of the two types of safety performance (IRSV and ISSV). Second, prior research on the impact of SSL on safety violations has often focused on a single mediating variable at the organizational level [28, 38], which leaves the complex path relationship between SSL and the multiple dimensions of safety violations unexplained. In this regard, by referring to Self-Determination Theory, Social Cognitive Theory and Social Information Processing Theory, we consider three mediating variables— group safety norms at the organizational level, safety motivation of workers at the individual level, and self-efficacy— drawing from Self-Determination Theory, Social Cognitive Theory, and Social Information Processing Theory. These variables are examined to reveal the mechanisms mediating the relationship between SSL and safety violations. Finally, it is expected that the results of the study will help management to target the improvement of different types of safety performance among construction workers through different types of SSL in practice. Meanwhile, this is also expected to contribute to the sustainable development of safety management in construction workplaces.
The remainder of this paper is structured as follows. The next part comprises the literature review, which lays the groundwork for research hypotheses through a comparative and analytical examination of current research. The third part presents information on the data collection and research design, followed by the data analysis and results. After the discussion of the findings, the conclusion, the limitations and perspectives for future research are presented.
Literature review
Safety violations
Construction safety violations are the opposite of safety compliance, referring to behaviors intentionally carried out by construction workers during the operation process, which, although unintentionally causing any harm, violate the organizational safety system and procedures [7, 40]. Safety violations are usually categorized into two dimensions: individuals’ routine safety violations (IRSV) and individuals’ situational safety violations (ISSV). IRSV refer to the intentional circumvention of safety systems, procedures, or practices by workers to achieve organizational (e.g., timely completion of work tasks) or personal (e.g., saving time or physical effort) benefits. When committing routine safety violations, workers habitually choose the most physically efficient operation or a “shortcut” [41]. In contrast, IRSV and ISSV result from situational constraints in the workflow that render compliance with the safety system impractical [42]. For instance, an operator may violate a safety system when protective equipment is unavailable. The main difference between these types of safety violations lies in whether they are caused by situational constraints. Existing studies indicate that situational and routine safety violations are influenced by different antecedent variables. For example, Liang et al. [39] found that workers’ perceived social support and safety motivation affect ISSV, while perceived production stress and ambivalent attitudes affect IRSV. Another study by Liang and Zhang [40] concluded that workers with low education levels are more likely to violate situational safety regulations, while inexperienced workers are more inclined towards routine safety violations. On this basis, this study also classified construction workers’ safety violations into IRSV and ISSV. It explored the intrinsic mechanisms between the different dimensions of supervisor safety leadership and these two types of safety violations.
Supervisors’ safety leadership (SSL)
Definition of SSL
Existing research has conceptualized “safety leadership”. For instance, Wu [33] defined safety leadership as “the interactive process by which leaders influence their followers to achieve organizational safety goals in the context of organizational and individual factors”, a definition widely accepted. Based on this perspective, safety leadership is a process, a leader’s influence on subordinates in group contexts and aimed at shared safety goals. Numerous studies have advocated that supervisors be placed at the center of safety interventions for construction workers [21, 43]. Despite lower positions in the management structure and the least authority, supervisors have the most frequent and close contact with workers and play a crucial role in construction safety management [7]. Supervisors enforce virtually all safety-related policies and regulations, coordinating subordinate work assignments. They oversee on-site operational activities and serve as intermediaries for communicating workers’ safety concerns, questions, and requests to top management [21]. In conjunction with these responsibilities, this paper defines the concept of “supervisors’ safety leadership (SSL)” in construction projects as “the safety competencies and means that supervisors possess during the construction process, which are able to influence construction workers and guide them to complete their production tasks safely”.
Dimensions of SSL
In terms of the dimensions of SSL, this study referred to the dimensions defined by Wu [16] and Wu [33]. According to these two studies, the SSL should consider characteristics of transformational leadership and transactional leadership, as the paradigms of transactional and transformational leadership are comprehensive enough to measure and understand leadership structures. However, before the analysis of these dimensions, it is crucial to have a certain understanding of transformational leadership and transactional leadership.
Transformational leadership emphasizes change [5]. It is designed to enable employees to clearly understand their responsibilities and obligations through flexible and varied leadership styles, thereby stimulating a higher level of cognition. Consequently, employees can achieve higher levels of performance by tapping into their potential to a greater extent [5]. In the context of construction workers’ safety performance, transformational leadership influences through four dimensions: idealized influence or charisma (behavioral role model), visionary motivation (developing subordinates’ commitment to goals), intellectual stimulation (helping subordinates solve problems intellectually and operationally), and personalized care (understanding and empathizing with subordinates) [29]. On the other hand, Barling et al. [15] systematically outlined four distinguishing characteristics of transactional leadership, including clear hierarchical relationships, good order, attention to rules, and obsessive control.
Transformational leadership behavior favors employee-centeredness, promoting performance by coaching employees on skills and ideas while expressing concern and encouragement. In contrast, transactional leadership tends to be more manager-centered, emphasizes clear work-management hierarchy boundaries, and promotes a controlled work environment through a forceful leadership style. On the basis of the two leadership styles and the characteristics of supervisors in the construction industry, this study identified three dimensions of SSL: Safety Coaching (SCoa), Safety Controlling (SCon), and Safety Caring (SCar). Safety coaching and safety caring align with aspects of transformational leadership; safety controlling is closely linked to transactional leadership [33]. These dimensions are defined as follows: SCoa means that supervisors can be a role model for workers to learn from, can provide guidance on daily operations; can mobilize their intellect; can share ideas; and can involve workers in decision-making [33, 34]. SCon refers to the extent to which supervisors set standards of behavior for workers according to a system of rules; use authority to correct violations; and use technology to monitor safety performance [33, 34]. SCar includes considering problems from the perspective of construction workers, listening to their safety feedback patiently, understanding their safety requirements, considering their safety concerns, and providing timely safety support and help in action [33, 34].
SSL and safety violations
SSL has been shown to be highly effective in improving human safety behavioral performance. For example, Dickerson et al. [44] argued that behavior-based safety coaching is a successful strategy for reducing errors in the context of industrial occupational safety. Leader coaching behavior can effectively guide subordinate safety behavior [45]. Kapp [28] and Petitta et al. [46] both pointed out that strong safety control can directly enhance workers’ safety performance and reduce the frequency of their mistakes. Liu et al. [47] found that safety support from superiors can directly and positively influence employees’ safety citizenship behavior. Based on these findings, we argue that SSL can attenuate worker safety violations and propose hypotheses 1 and 2.
H1: Three sub-dimensions of SSL, namely Safety coaching (H1a), Safety controlling (H1b), and Safety caring (H1c), have negative influences on ISSV.
H2: Three sub-dimensions of SSL, namely Safety coaching (H2a), Safety controlling (H2b), and Safety caring (H2c), have negative influences on IRSV.
Safety motivation as the mediating variable
Safety motivation (SM) refers to an individual’s willingness to make efforts to achieve safety and the corresponding actions, reflecting the importance employees attribute to safety [48–50]. Previous research conceptualized safety behavior as an interaction between proximal individual differences (e.g., safety motivation, etc) and distal situational factors (e.g., leadership or safety management, etc). Therefore, safety leadership has been recognized as an important antecedent of safety motivation. Current research has confirmed this relationship. For example, Kovjanic et al. [51] argued that when supervisors provide careful instruction and safety care, these high-quality behaviors resonate with workers and enhance their sense of identification with the organization, which helps workers foster safety motivation. Probst and Brubaker [52] noted that workers’ safety motivation relates to supervisors’ perceptions of safety policy enforcement, including the extent to which supervisors commend safety compliance and sanction non-compliance. Inadequate enforcement by supervisors correlates with low levels of worker safety motivation. Based on the above discussions, hypothesis 3 is proposed:
H3: Three sub-dimensions of SSL, namely: Safety coaching (H3a), Safety controlling (H3b), and Safety caring (H3c) have positive influences on SM
In addition, existing research generally recognizes safety motivation as a key determinant of whether an individual makes safety violations [39]. Safety motivation can significantly enhance employees’ level of safety compliance [53–55]. However, the extent to which safety motivation plays a role in safety violations may vary depending on the nature of the violations. For example, when workers still choose to adhere to safety rules without safety protective equipment, they may need more safety motivation. On the contrary, if they are adhered to just to comply with safety procedures, the effectiveness of safety motivation may be relatively low [48]. Therefore, hypothesis 4 is proposed to test the effect of safety motivation on different types of safety violations:
H4: SM have negative influences on two sub-dimensions of safety violations, namely: ISSV (H4a) and IRSV (H4b)
On the basis of hypotheses 3 and 4, we further combine the Self-Determination Theory (SDT) to explain the mediating role of safety motivation between SSL and safety violations: SDT recognizes human beings as positive organisms with innate potential for psychological growth and development [56]. However, these intrinsic potentials often require external stimuli for reinforcement and gradually develop into control over behavior. Therefore, key external environmental variables (e.g., leadership) help stimulate autonomous motivation in employees to further drive their growth and progress [51]. Therefore, hypothesis 5 is proposed:
H5: SM can mediate the relationship between SSL and safety violations: SM can mediate the relationship between the three sub-dimensions of SSL (Safety coaching (H5a), Safety controlling (H5b), and Safety caring (H5c)) and ISSV. SM can mediate the relationship between the three sub-dimensions of SSL (Safety coaching (H5d), Safety controlling (H5e), and Safety caring (H5f)) andIRSV.
Group safety norm as the mediating variable
Group safety norm (GSN) indicates the social pressure to perform safety behavior, namely, what others expect the individual should undertake to perform tasks safely. It is a collective cognition of a group [57]. The common belief of group is formed by the interaction between internal members. The interaction occurs not only between workers, but also between workers and their direct leaders [21, 58]. Previous studies have affirmed the pivotal role of supervisors and their leadership in the formation of safety-related group norms in construction teams. For example, Fang et al. [21] found that the training and prevention behavior performed by supervisors significantly affects the group-level safety climate, including the involvement and mutual influence of workers. McFadden et al. [59] argued that reasonable control over employees can effectively cultivate positive group safety norms. He et al. [60] stated that a high-quality leader-member exchange relationship directly and positively affects the safety climate of the team. Based on the above discussions, hypothesis 6 is proposed:
H6: Three sub-dimensions of SSL, namely: Safety coaching (H6a), Safety controlling (H6b), and Safety caring (H6c) have positive influences on GSN
Moreover, due to the complexity of the construction site, formal rules cannot regulate every aspect of workers’ behavior at all. Behavior changes driven by social norms are more sustainable and effective, especially when such social norms spread to the work groups [61]. Under such an environment, the safety behavior of workers can be improved unconsciously, and they will do their best to avoid violations. Therefore, hypothesis 7 is proposed:
H7: GSN have negative influences on two sub-dimensions of safety violations, namely: ISSV (H7a) and IRSV (H7b)
Based on hypotheses 6 and 7, we further combine the Social Cognition Theory to explain the mediating role of group safety norm between SSL and safety violations: according to social cognition theory, individual workers always try to belong to a social group and adjust their behavior to what they perceive as socially acceptable within the crew [62]. Despite the belief in the effectiveness of GSN in mitigating the relationship between SSL and worker safety violations, few studies have synthesized the multidimensionality of SSL and safety violations. Therefore, hypothesis 8 is proposed:
H8: GSN can mediate the relationship between SSL and safety violations: GSN can mediate the relationship between the three sub-dimensions of SSL (Safety coaching (H8a), Safety controlling (H8b), and Safety caring (H8c)) and ISSV. GSN can mediate the relationship between the three sub-dimensions of SSL (Safety coaching (H8d), Safety controlling (H8e), and Safety caring (H8f)) and IRSV.
Self-efficacy as the mediating variable
In the field of safety, workers’ self-efficacy refers to “workers’ estimates and judgments of their ability to accomplish safety-related goals and tasks” [63]. Evidence has shown that in safety critical industries, the involvement of supervisors in safety management can effectively enhance the self-efficacy of subordinates towards safety rules. Similarly, the positive relationship between SSL and employees’ self-efficacy has been widely demonstrated. Bono and Ilies [64] suggested that subordinates emulate the exemplary behavior of their supervisors to stimulate their own positive feelings and efficacy. Fugas et al. [65] argued that supervisors’ “injunctive norms” contribute to workers’ accurate perceptions of their own abilities and motivate them to surmount difficulties. In addition, care and support from supervisors have been identified as effective drivers of self-efficacy [66]. However, few studies have comprehensively compared the differences in the impact of different dimensions of SSL on self-efficacy. Based on the above discussions, hypothesis 9 is proposed:
H9: Three sub-dimensions of SSL, namely: Safety coaching (H9a), Safety controlling (H9b), and Safety caring (H9c) have positive influences on SE
Additionally, several studies have reported a positive relationship between workers’ self-efficacy on safety performance. For instance, Yen et al. [67] and Saleem et al. [68] both concluded that workers’ self-efficacy positively affects their safety compliance. Kim and Jang [69] revealed that safety self-efficacy is a key skill for individuals to inhibit human errors and thus avoid potential accidents. Therefore, we believe that the self-efficacy of workers can reduce the probability of safety violations and thus propose hypothesis 10:
H10: SE have negative influences on two sub-dimensions of safety violations, namely: ISSV (H10a) and IRSV (H10b)
Based on hypotheses 9 and 10, we further combine the Social Information Processing (SIP) theory to explain the mediating role of self-efficacy between SSL and safety violations: according to SIP, an individual processes information based on their understanding of how cognitive and behavioral responses come about through social interactions [70, 71]. Since behaviors, attitudes, and perceptions are affected by social information, all aspects of individual behaviors, attitudes, and perceptions are presented as a result of cognitive products of information processing [72, 73]. In construction workplaces, workers heavily rely on cues or signals from leaders to confirm their understanding of the environment in the organization and adjust their cognitions accordingly. Thus, in explaining the link between safety leadership and safety violations, we hypothesized a mechanism that could potentially mediate this relationship. From this perspective, workers’ self-efficacy was identified as another mediator at the individual level. Therefore, hypothesis 11 is proposed:
H11: SE can mediate the relationship between SSL and safety violations. SE can mediate the relationship between the three sub-dimensions of SSL (safety coaching (H11a), safety controlling (H11b), and safety caring (H11c)) and ISSV. SE can also mediate the relationship between the three sub-dimensions of SSL (Safety coaching (H11d), Safety controlling (H11e), and Safety caring (H11f)) and IRSV.
Based on the above analysis, the complete research model of this paper is shown in Fig. 1.

The hypothesized model regarding the supervisors’ safety leadership-safety violations relationship.
Participants and procedures
The questionnaire survey was conducted between 01/05/2023 and 31/08/2023. Data were collected using both electronic and paper questionnaires. A valid survey link was provided through the questionnaire website (Question-star) for respondents to fill in the questionnaire. As per the research scope from the perspective of construction workers, 500 paper questionnaires were distributed to frontline construction workers in major Chinese cities, including Shanghai, Suzhou, Nanjing, Chongqing, Xi’an and Wuhan. We collected 255 paper questionnaires and 198 online questionnaires. After excluding those that did not meet the requirements, 195 valid paper questionnaires and 151 online questionnaires were finally recovered, with valid questionnaire recovery rates of 76.5% and 76.3%, respectively. A total of 346 valid questionnaires were recovered. The demographic information of the respondents is shown in Fig. 2. These sample characteristics are consistent with the nature and uniqueness of the construction industry.

Demographic information of the respondents. Note: *represents p < 0.05, **represents p < 0.01.
We adapted previously validated measurement scales and developed specific scales for use in the construction context. Before the formal scale was finalized, the original English questions were translated into Chinese following standard translation procedures, followed by a panel discussion among five experts in the field of engineering safety to determine the final measurement scales (e.g., incorporating industry experience and knowledge). Each measurement question was rated on a Likert 5-point scale ranging from 1 (strongly disagree) to 5 (strongly agree). Table 1 shows the variables, measures of study variables, number of items, and supporting literature.
Variables, measures of the studied variables, number of items, and supporting literature
Variables, measures of the studied variables, number of items, and supporting literature
A 19-item scale was used in this study to assess each worker’s perceptions of safety leadership across three adapted subscales: Safety coaching, Safety controlling and Safety caring [33]. Sample question items include, “My supervisor helps workers realize the importance of safety” (SCoa), “My supervisor orders us to be determined to accomplish safety goals” (SCon), “My supervisor works hard to meet our safety needs” (SCar), etc.
The scale used to measure worker safety motivation was selected from the validated scale developed by Nykanen et al. [74], which measured safety motivation among vocational high school students with three items. We fine-tuned its content by incorporating the context of the construction safety industry (one of the sample items was “I feel that working to maintain or improve my personal safety is worthwhile”).
To measure worker group safety norms, we adapted a scale from the work of Su et al. [7]. This scale contains five items to assess workers’ perceptions of whether fellow team members recognize certain behaviors. One of the sample items is: “Members within our shift would strongly disapprove of behavior that violates safety rules and regulations”.
The scale used to measure workers’ self-efficacy was selected from the Psychological Capital Scale developed and validated by Luthans et al. [75], which measured employees’ self-efficacy using six items. We adjusted it to incorporate the context of the construction safety industry (one of the sample items was: “I believe that I can always analyze problems and find solutions independently”).
The questions for assessing both routine and situational safety violations were adapted from the self-report items validated by Chmiel et al. [35] and Su et al. [7]. Routine safety violations were measured with four items, with a high score indicating a greater frequency of violations. A sample item reads, “I’ll take shortcuts to get the job done if I can make it easy”. Situational safety violations were measured with six items and were reversely scored: a high score indicated a low level of violations. A sample item is “Even if it’s inconvenient sometimes, I always wear a safety helmet”.
The data analysis was conducted in three stages using SPSS 21.0 and AMOS 24.0 software. First, SPSS 21.0 was used for descriptive analysis. Second, reliability tests were conducted using SPSS 21.0, and AMOS 24.0 was used for confirmatory factor analysis (CFA) to test the dimensionality and discriminant validity of our multiple-item measures, and metrics were calculated to test convergent validity. Finally, all hypotheses (across the entire model) were tested (see Chapter 4), including tests for direct effects between variables as well as mediating effects (using AMOS 24.0 software).
Descriptive analyses
Table 2 shows the results of the descriptive statistical analysis. The smaller standard deviation indicates a lesser degree of variation in the data, which means that the participant’s level of understanding and answers to the questions were at an acceptable level. In addition, the absolute values of kurtosis for each variable are less than 7 and the absolute values of skewness are less than 3. These observations suggest that the variables follow a normal distribution and are suitable for analysis [76–78].
Results of the descriptive statistical analysis
Results of the descriptive statistical analysis
The internal consistency of the variables underwent verification through a reliability test. Cronbach’s α coefficient was used to quantify reliability with a lower threshold value of 0.6–0.7 [79]. It can be seen that the Cronbach’s α values of the variables are greater than 0.8 (shown in Table 3), indicating strong reliability.
Results of the variables’ convergent validity
Results of the variables’ convergent validity
Confirmatory factor analysis (CFA) was used to test the validity of the measurement model. The validity test usually consists of two parts: the convergent validity test and the discriminant validity test. Convergent validity assesses the extent to which the latent variables can be measured and explained by their observed variables. It is assessed using three metrics: standardized factor loadings (SFL), combined reliability (CR), and average variance extracted (AVE), with recommended thresholds of 0.5, 0.7, and 0.5, respectively. The results show the SFLs are all above 0.5 [80], while the CR and AVE values are above 0.7 and 0.5, respectively [81] (shown in Table 3). Therefore, the convergent validity is deemed acceptable.
Discriminant validity assesses the degree to which a latent variable differs from other latent variables and can be measured by comparing the square root of the variable AVE with its maximum correlation coefficient. When the former is greater than the latter, the variables are considered to have good discriminant validity [82]. For instance, the square root value of AVE for SCoa is 0.826, greater than its maximum correlation coefficient with SM of 0.442. This indicates that SCoa demonstrates acceptable discriminant validity. Similarly, as shown in Table 4, the other seven variables also show good discriminant validity.
Discriminant validity test
**p < 0.01. Note: diagonal values are the square roots of average variance extracted (AVE).
After analyzing the reliability and validity of the variables, the hypotheses in the model require further testing. Our hypotheses contain direct paths as well as mediated paths between the variables, so both types of relationships need to be tested in turn.
Structural model fit
To clarify the direct influence relationship among the variables, we analyze the model composed of all variables using AMOS 24.0 software. The first step is to determine the validity of the structural equation model [83], mainly gauged through the measurement of some fit indicators [84, 85]. The model fit metrics and their corresponding criteria are shown in Table 5. All metrics meet the criteria except for the NFI, which is close to 0.9. This suggests an acceptable overall model fit.
Model goodness-of-fit index
Model goodness-of-fit index
Note:χ2/d f= Chi-squared degrees of freedom ratio; RMSEA = Root-mean-square error of approximation; IFI = Incremental fit index; NFI = Normed fit index; TLI = Tacker-Lewis index; CFI = Comparative fit index.
Figure 3 demonstrates the final estimation results of the structural model together with the standardized path coefficients and their respective significance levels. On this basis, the standardized path coefficients (β), critical ratio (C.R.) values, p-values, and hypothesis testing results of the model are presented more visually in Table 6. The path coefficients (β) reflect the relationship between the variables and their respective degrees of influence, while the C.R. determines the significance of regression coefficients. The C.R. value equal to or greater than 1.96 indicates significance at a p-value less than 0.05 [84].

The structural model and impact paths.
Summary table of path coefficients for fitted models
Note: *represents p < 0.05, **represents p < 0.01, ***represents p < 0.001; Coefficient (β) = standardized regression weight; CR= critical ratio (> [1.96]); = hypothesis is partially supported; ✓= hypothesis is supported; û = hypothesis is rejected.
As seen in Fig. 3 and Table 6, among the three dimensions of SSL, only SCar exhibits a significant effect on ISSV (β= –0.159, p < 0.05). Therefore, only H1C holds for hypotheses H1a-c. Furthermore, only SCoa has an effect on IRSV (β= –0.161, p < 0.05). Therefore, only H2a holds true for hypotheses H2a-c. SCoa, SCon, and SCar all positively affect SM (β= 0.167, 0.232, 0.581, p < 0.001), confirming the validity of H3a-c. However, SM only influences ISSV (β= –0.469, p < 0.001), thus only supporting H4a in H4a-b. GSN is positively influenced by SCon and SCar (β= 0.383, 0.360, p < 0.001), thus validating H6b and H6c in H6a-c. However, GSN only influences ISSV (β= –0.230, p < 0.001), hence, only H7a is upheld within H7a-b. Finally, SE is only positively affected by SCoa (β= 0.199, p < 0.01). Thus, only H9a is supported within H9a-c. However, SE only influences IRSV (β= –0.428, p < 0.001), confirming only H10b in H10a-b.
To understand the mediating role of workers’ safety motivation, group safety norms, and self-efficacy, the bootstrap method was used [86]. The mediating effect was tested by 2000 iterations, calculating 95% confidence intervals.
We provide a more intuitive list in Table 7, detailing the mediation effect values, 95% confidence intervals, and hypothesis testing results for each mediation pathway. For example, considering the SCoa⟶SM⟶ISSV path, the mediation effect value is –0.089. The upper and lower 95% confidence intervals exclude 0, and the p-value is less than the significant level of 0.05, indicating a mediation effect in the path. Similarly, the standardized indirect effects of SCon and SCar on ISSV through SM are (–0.113, p < 0.01, 95% CI [–0.207, –0.048]) and (–0.263, p < 0.01, 95% CI [–0.418, –0.146]), respectively. Therefore, hypotheses H5a, b, and c are all hold. Conversely, for the SCoa⟶SM⟶IRSV path, the mediation effect value is – 0.041. The upper and lower 95% confidence intervals contain 0, and the p-value is greater than the significance level of 0.05, indicating the absence of a mediation effect in this path. Similarly, the standardized indirect effects of SCon and SCar on IRSV through SM are not statistically significant (95% confidence interval including 0). Therefore, hypotheses H5d, e, and f are not hold. Hypothesis H5 is partially supported. In addition, the standardized indirect effects of SCon and SCar on ISSV through GSN are (–0.091, p < 0.01, 95% CI [–0.177, –0.036]) and (– 0.08, p < 0.01, 95% CI [–0.164, –0.028]), respectively. Thus, hypotheses H8b, and c are all hold. The standardized indirect effect of SCoa on ISSV through GSN and the standardized indirect effects of SCoa, SCon, and SCar on IRSV through GSN are not statistically significant (95% confidence interval including 0). Therefore, hypotheses H8a, d, e, and f are not hold. Hypothesis H8 is partially supported. Furthermore, the standardized indirect effect of SCoa on IRSV through SE is (– 0.121, p < 0.05, 95% CI [–0.226, –0.024]). Therefore, hypothesis H11d holds. However, the standardized indirect effects of SCoa, SCon and SCar on ISSV through SE and the standardized indirect effects of SCon and SCar on IRSV through SE are not statistically significant (95% confidence interval including 0). Therefore, hypotheses H11a, b, c, e, and f are not hold. Hypothesis H11 is partially supported.
Summary of estimated indirect effects based on the bootstrap method
Summary of estimated indirect effects based on the bootstrap method
Note: = hypothesis is partially supported; ✓= hypothesis is supported; ✗= hypothesis is rejected.
This research has constructed a theoretical model that explains the intrinsic relationship between frontline supervisors’ safety leadership and workers’ safety violations. Compared to previous studies [7], this study aims to gain a more detailed understanding of the intrinsic association between SSL and worker safety violations. By integrating the self-determination theory, social cognitive theory, and social information processing theory, we argue that, at the individual level, SSL enhances workers’ safety motivation (SM) and sense of self-efficacy (SE), thereby influencing workers’ safety violations. At the organizational level, SSL uses group safety norms (GSN) as a bridge to influence construction workers’ safety violations. Meanwhile, a theoretical model was constructed and validated by subdividing SSL into three dimensions: safety coaching (SCoa), safety controlling (SCon), and safety caring (SCar). Similarly, worker safety violations are subdivided into individuals’ situational safety violations (ISSV) and individuals’ routine safety violations(IRSV).
The direct relationship between SSL and safety violations
The tests conducted on hypotheses 1 and 2 show that only two paths, SCar⟶ISSV (H1c) and SCoa⟶IRSV (H2a), hold. Few studies have been able to account for this result. Therefore, we propose a possible explanation for the direct impact of safety caring on ISSV. As mentioned in Section 2.1., ISSV is caused by situational constraints during construction work (such as safety equipment not being easily accessible, etc.). We argue that resource support and emotional care from supervisors directly benefit workers. When supervisors provide care and support, workers’ safety needs are met and safeguarded, thereby removing situational constraints that impede their safety compliance [22]. As a result, their situational violations are diminished. In response to the direct influence of safety coaching on IRSV, we argue that within construction crews, workers tend to look to the supervisor as an opinion leader and seek their guidance to determine operational procedures [24]. Therefore, individual behavior is influenced by supervisors’ demonstration of safety behavior. It can be inferred that some of the individual’s undesirable behavior (e.g., failure to comply with safety procedures) also mostly comes from the imitation of supervisors’ erroneous safety coaching. Meanwhile, compared to other roles, the influence of supervisors is often more effective [43], which leaves a deeper impression on workers and leads to their daily and ongoing safety violations.
The mediating mechanisms between SSL and safety violations
The mediating effect of SM
The analysis of hypotheses H3, 4, and 5 found that all three dimensions of supervisor safety leadership positively affect workers’ safety motivation (SM). However, SM demonstrates a significant correlation only with ISSV, and it mediates the relationship between SCoa, SCon, SCar, and ISSV. However, we found notable differences in the effects of the three sub-dimensions of supervisor safety leadership on SM. Specifically, SCar exhibits a significantly stronger influence on SM compared to SCoa and SCon, with a path coefficient of 0.581 in contrast to 0.167 and 0.232 for the other two. Thus, there is a stronger association between supervisors’ safety caring and ISSV caused by situational constraints and their relationship is mainly mediated by the safety motivation of workers. That is, when supervisors care about their workers, provide safety resources, and seek their well-being, on the one hand, workers’ safety needs are more comprehensively guaranteed, so that workers do not fall into the embarrassment of passive violations due to lack of access to personal protective equipment (PPE) [39]. On the other hand, this supportive work environment also effectively motivates workers to engage in safety practices (e.g., helping coworkers obtain PPE in a more timely manner; giving their own and their coworkers’ safety needs timely feedback to their superiors, etc.) [39, 87]. As a result, workers’ situational safety violations are reduced. This finding not only supports the argument made by Chmiel et al. [35] that worker participation in non-coercive safety activities will reduce situational safety violations but also further elucidates that the distal antecedent of this mechanism is supervisors’ safetycaring.
The mediating effect of GSN
The analysis of hypotheses H6, 7, and 8 showed that two dimensions of supervisor safety leadership (SCon and SCar) positively influenced workers’ group safety norm (GSN) and that GSN mediated the relationship between SCon, SCar, and ISSV. This suggests that supervisors can influence worker safety behavior by establishing positive group norms. Although previous studies as well as our validation results suggest that care and support from supervisors reflect a strong supervisor-worker relationship and contribute to the creation of a favorable group climate [7]; our findings show that workers’ GSN is primarily influenced by supervisors’ safety controlling. This indicates that supervisors are more likely to play a more “assertive” role in creating an environment that places a high value on safety compliance [29]. Clearly, one way to achieve this is by exercising control over team members by fulfilling their roles and dictating what is expected of them (i.e., prohibitive norms), which seems to be more direct and effective [65]. In a group with high safety standards, workers will supervise each other and remind each other of precautions. Therefore, this effectively reduces violations caused by situational restrictions (e.g., forgetting to wear a safety helmet, etc.) [7]. Furthermore, the significant correlation between GSN and ISSV further supports the view that ISSV is closely related to workers’ psychosocial processes to a greater extent [7, 35].
The mediating effect of SE
The analysis of hypotheses H9, 10, and 11 showed that only SCoa positively influenced workers’ self-efficacy (SE), and SE mediated the relationship between SCoa and IRSV. SE reflects workers’ estimation and judgment regarding their ability to accomplish safety-related goals and tasks [67]. While supervisors’ safety coaching serves to exemplify workers’ behavior and mobilized workers’ intelligence, workers also benefit from substantial technical support [64]. This support fosters a greater sense of control over the safety situation at the site so as to enhance confidence levels. Under the effective coaching of supervisors, workers’ cognitive levels undergo a significant enhancement. Consequently, they carry out their daily tasks in a more standardized and quality-assured manner, rather than omitting some necessary safety steps in order to expedite tasks quickly or to save time and physical exertion. In addition, SE is only associated with IRSV, which further supports the argument made by Hansez and Chmiel [36] that routine safety violations involve a cognitive-energetic mechanism. High levels of SE among workers imply superior cognitive abilities, whereas high levels of SE derive from high levels of safety coaching from supervisors. Therefore, compared to previous studies [36, 88], our research findings may suggest a more complete pathway mechanism, namely: observational learning ⟶ ability enhancement ⟶ individual behavioral decision-making.
Theoretical contributions
The findings of this study yield significant theoretical contributions to the study of leadership behavior and occupational health and safety in the construction industry. While Current research on construction safety violations still focuses on organizational or individual factors, there have been relatively few studies on SSL. To the best of our knowledge, this is the first study to explore the multiple mediating mechanisms of the relationship between SSL and individuals’ safety violations from the perspective of construction workers. Therefore, this study offers some meaningful empirical insights into construction safety management. For example, three dimensions of SSL and three mediating variables were established to relate to different organizational and individual levels. This multidimensional analysis has addressed a limitation in previous safety leadership research, which tends to relate to organizational-level mediating variables. On this basis, the direct and indirect effects of three leadership characteristics on two types of safety violations (routine and situational) have been clarified. The results of the study highlight safety caring from supervisors can better stimulate the willingness of workers to actively engage in safety related actions, thereby reducing the probability of situational safety violations. In addition, supervisors’ safety controlling can be more effective in creating a good group safety climate. In such an organizational environment, workers are constantly subjected to good conduct and professional safety terms, which make them less susceptible to breaches of safety rules. Furthermore, supervisors’ safety coaching enhances workers’ competence and confidence, thereby promoting sustained adherence to safety protocols. As a result, this evidence-based research can inform the development of targeted interventions designed to effectively reduce both types of workers’ safety violations, namely, ISSV and IRSV. Therefore, this study clarifies the complex relationships between supervisor behavior and safety outcomes, particularly from the perspective of construction workers and their perceptions of supervisors’ actions and leadership.
Practical implications
This study offers practical implications for construction safety management. Firstly, top management in the construction industry should prioritize education and training for frontline supervisors to enhance their skills, safety competence, and correct safety behavior [89]. In this way, these principles penetrate the organization from the top down, and the workers learn through emulation coupled with the supervisors’ correct safety coaching; workers can significantly improve their safety competence and confidence to ensure diligent performance of safety duties. Secondly, supervisors should create a positive safety climate at the workplace by communicating the principle of “safety first” to workers. This involves a pattern of high expectations, high standards of supervision, and rewards and penalties. Through the establishment of “prohibitive norms” within the organization, worker groups can demonstrate high standards of safety behavior, and workers will remind and help each other to adhere to these regulations. Moreover, supervisors should increase their caring for workers’ living conditions, take flexible measures to meet sensible and reasonable work requirements within the organizational framework, offer increased encouragement to employees and humbly accept workers’ safety-related suggestions. The integration of humanistic care and respect for individuality within institutional constraints greatly improves workers’ satisfaction and recognition of their supervisors [90]. This approach also better shapes workers’ safety values and creates stronger motivation among employees to prioritize safety in their work.
Conclusion
Using a theory-driven model, this study uncovered the impact of different dimensions of SSL (namely, safety coaching, safety controlling, and safety caring) on two types of safety violations (namely, routine and situational) from the perspective of construction workers. Safety coaching directly predicted workers’ routine safety violations, while safety caring directly predicted situational safety violations. More importantly, different types of SSL can affect different types of safety violations through different mediators. Specifically, workers’ safety motivation was more likely to be influenced by supervisors’ safety caring, which reduced their situational safety violations; the establishment of group safety norms among workers depended primarily on supervisors’ safety controlling, which further reduced their situational safety violations; and supervisors’ safety coaching influenced routine violations by acting primarily on workers’ self-efficacy. Safety motivation, group safety norms, and self-efficacy play important roles in the different pathways between SSL and safety violations and serve as significant predictors of safety violations. These findings suggest that interventions from a supervisor’s perspective can effectively guide workers to develop good safety intentions, boost their confidence in working safely and create a favorable group safety climate. Consequently, such interventions contribute to the establishment of a more stable and secure construction work environment.
Some limitations should be acknowledged in this study. Firstly, the generalizability of the results may be limited as the survey was confined to certain regions of China with a single industry. Future research could explore safety violations in other industries or cultures to gain a deeper understanding of safety violations and effective safety leadership through a more diverse sample. Secondly, the data collection of the sample was done using the cross-sectional method, which may be prone to social desirability biases. Factors such as respondents’ personality traits, cognitive processes, job-related sentiments, different groups, and social influences from others may affect the measurement results. Future studies could conduct more in-depth interviews with program staff to reveal their differential perceptions regarding their approach to the problem and weigh them in the design of the questionnaire.
Ethical statement
This research was approved by Research Ethics Committee, Jiangsu University. This is an original work that has not been published or submitted for publication elsewhere. The authors understand that submission of the paper means the copyright transfer from the authors to the publisher of WORK: A Journal of Prevention, Assessment & Rehabilitation.
Informed consent
Informed consent was obtained from all participants. The manuscript does not contain any identifiable individual data in any form.
Conflict of interest
The authors declare that they have no conflict of interest.
Footnotes
Acknowledgments
The authors would like to thank the anonymous reviewers for their invaluable and constructive comments.
Funding
This work was funded by the National Natural Science Foundation of China (Nos. 72071096, 71971100, 72101055); sponsored by Qing Lan Project of Jiangsu Province.
