A Conceptual Model of Safety Culture Indicators for Railway Transport: Integrating Continuous Improvement and Sustainability

The importance of safety culture in high-risk sectors such as railway transport has gained increasing prominence, particularly within the evolving European regulatory landscape. Commission Delegated Regulation (EU) 2018/762 requires railway organisations to establish strategies for the continuous improvement of safety culture, emphasizing both behavioural and systemic dimensions of safety. This paper presents a structured literature review and proposes a conceptual model of performance indicators designed to support the implementation of these strategies in railway enterprises. Drawing on established continuous improvement methodologies—Kaizen, Six Sigma, and the DMAIC (Define–Measure–Analyse–Improve–Control) framework—the model aligns with Safety Management System (SMS) and Maintenance Management System (MMS) processes. The proposed indicators encompass domains such as risk assessment, change management, employee competence, incident reporting, and system monitoring. The model aims to transform railway organisations into learning systems capable of proactively adapting to emerging risks, including those related to cybersecurity as addressed by the NIS2 Directive. Through a structured literature review and conceptual synthesis, this study provides a theoretical foundation for the integration of continuous improvement and sustainability in safety management. The findings offer practical guidance for policymakers and railway operators seeking to strengthen data-driven, resilient, and sustainable transport safety governance in the European context.