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

A longitudinal approach was used to measure safety climate at a large-scale harbor expansion construction project. The project was commissioned by a single client and undertaken simultaneously by several principal contractors. Two-wave safety climate surveys were conducted at four principal contractors' sites: 1) at the early stage of the project, and 2) between 5 to 8 months after the first survey. Each survey measured workers' perceptions of safety response at different levels, i.e. client’s safety response (CSR), principal contractor’s safety response (PCSR), and supervisors' safety response (SSR). The survey data was analyzed using ANOVA. The results demonstrate that at the early stage of the project, the between-site variance in safety climate was only significant at the lower levels (i.e. the principal contractor and the supervisor levels), but not at the higher level (i.e. the client level). However, at the later stage, the between-site variance was significant at all the three levels. In a multi-level construction project organization, workers have few opportunities to directly interact with the client. They may partly form their perceptions of CSR through interpreting the safety policies and procedures implemented by the principal contractor to understand the client's safety expectations. However, at each construction site, the implementation of safety policies and procedures was specific to each principal contractor organization. Consequently, workers of different sites developed vastly different perceptions of PCSR, and this difference contributed to the larger between-site variance in workers' perceptions of CSR in the later stage of the project. Further, supervisors locally implemented the safety procedures within workgroups using discrepant interpretations and context-specific action directives. Therefore, workers of different sites had significantly different perceptions of SSR. The research provides preliminary evidence as to the impact of the characteristics of the construction project organizational structure on shaping workers' perceptions about safety response at various levels and highlights the potential of lower level safety response as an antecedent to the perception of higher level safety climate.