Safety climate as a multi-level and dynamic concept: exploring the variance at different levels over time

Safety climate was measured longitudinally at a large-scale harbour expansion construction project. The project was commissioned by a single client and undertaken simultaneously by several principal contractors. Two waves of surveys measured participants' perceptions of safety at different levels, i.e. the client's safety response (CSR), the principal contractors' safety response (PCSR), and the supervisors' safety response (SSR). The results demonstrated significant between-site variance in workers' perceptions of PCSR and SSR in early project stage. However, at the later stage, the between-site variance was significant at all three levels. In contrast, the between-site variance in managerial/professional/supervisory personnel's perceptions of CSR and PCSR was significant both at the early and later stages. In this project, individual contractors implemented company-specific safety policies and procedures to meet the client's requirements. Moreover, supervisors locally implemented safety procedures using discrepant interpretations and context-specific action directives. Consequently, between-site variance was observed in PCSR and SSR. Due to the limited direct interactions with the client, workers may gradually form their perceptions of CSR through making sense of the project environment and interpreting safety messages conveyed by contractors and supervisors, causing between-site variance in CSR at later stages. The research provides preliminary evidence as to the impact of the characteristics of construction project organizational structures on shaping workers' perceptions about safety at various levels.