2.2.6. Standardized Safety Rules and Procedures

Standardization in construction projects is difficult to achieve. Other high-risk industries, such as aviation and nuclear, usually have well-defined work procedures. Since the construction process is characterized by high variety and loose coupling, most of the construction work, to a significant extent, depends on employees' discretion and experience. Standardized safety rules and procedures make those rules and procedures easy to follow, and hence, contribute to an increase in safety behavior. However, the secondary effect of too much standardization should be restrained [29].

#### 2.2.7. Safety Climate

Safety climate is a perceptual, collective, and multidimensional phenomenon, referring to individuals' shared perceptions of how safety is valued in the workplace [3]. The impact of a safety climate on safety behavior has been well-documented. Safety climates can exert a direct influence on safety behavior, and also can impact safety behavior through mediators, such as the psychological contract [30], safety knowledge and motivation [31], etc.

### *2.3. Group Level Factors*

Construction workers usually move from project to project and may work with different main contractors, but they often work in a workgroups for a relatively long period. Therefore, compared with supervisors from the main contractor, workgroup supervisors usually have a bigger influence on construction workers [32]. This paper focuses on four phenomena at the workgroup level, i.e., supervisors' transformational leadership and contingent reward behavior (one aspect of their transactional leadership), leader–member exchange, and team–member exchange.

## 2.3.1. Transformational Leadership

Leadership refers to a process of motivating others to act toward shared goals. It involves setting goals, devising achievement methods, persuading others to accept these goals and achievement methods, and solving problems decisively and quickly. James M. Burns proposes two leadership styles: transactional and transformational. The transactional leader identifies the needs of employees and the organization, and then informs employees what to do to meet these needs. Beyond these needs, transformational leaders arouse and

satisfy higher needs within each individual. A transactional–transformational leadership paradigm is broad enough to capture the leadership construct.

Transformational leadership is positively associated with safety behavior. Shen et al. propose and validate a sequential mediation model to explain the impact of supervisory transformational leadership on construction personnel's safety behavior [10]. Hoffmeister et al. found that different facets of transformational leadership have a different impact on different sample's safety behavior [33]. In particular, idealized influence has an impact on safety compliance behavior in both the apprentice and journeyman samples, but it has an impact on safety participation behavior only in the apprentice sample.
